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240 Brakes and Big Brake Projects

     UPDATED: June 26, 2024     CONTACT   
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This page illustrates some cool brake upgrades for the Volvo 240.
Hopefully it will helps you if you decide to do some similar mods. 

If you have done something like this for your 240, I would really like to hear about it and see some photos.
Contact me if you have comments or can help improve this page: CONTACT
240 Brake Specs
240 Master Cylinders
240 Brake BOOSTERS
240 Brake Lines General Info
Brake Bleeding
Flaring Brake Lines
R-Brakes on a 240, FRONT only (began in 2003)
R-Brakes on a 240 FRONT and REAR BNE Front Brake Line Brackets
Brake Junction Blocks (Manifolds) R Brake Squeal and Shims
PROPORTIONING VALVE INFO

Wilwood 240 Front Brakes (began 2010)
BNE Brembos for 240
RX7 Front Brakes
Porsche Cayenne Brakes Cadillac ATS Brakes
Dick Prince 240 Racecar Brakes
Renault Megane Calipers
XC90 front Caliper, Rotors on a 240
Miscellaneous Brakes Stuff

Alternate Master Cylinder Specs Info
VACUUM PUMP to Improve LOW Brake Booster VACUUM (2024)
HYDROBOOST and other Conversions for 240
Electric Brake Booster Conversions

Compact REMOTE Electric Brake Booster

Some good DIY 240 brake discussions:
https://forums.turbobricks.com/showthread.php?t=333898
https://forums.turbobricks.com/showthread.php?t=280552
https://forums.turbobricks.com/showthread.php?t=306620
https://forums.turbobricks.com/showthread.php?t=288017


PERFORMANCE BRAKE PADS
Before putting Big Brakes on my 240:
I owned my '84 245 Turbo for 6 years before doing the big R-caliper upgrade below.  I had plenty of experience with stock 240 brakes and pads and lots of experience trying different things to improve them.  Stock 240 brakes are OK for most "normal" driving.  In my opinion they are really not good enough for track or high-performance driving.

I was already a customer of IPD, so naturally I tried some of their brake pads over the years.  I tried the PBR Deluxe first. I discovered the PBR pads had a bad tendency to fade after a few hard stops.
The fading wasn't subtle... it was really bad.
The braking came back once things cooled down.  The PBR Deluxe pads are really good when cold... lots of bite, and very little brake dust.  Just don't expect much out of them after when hot hard stops. They will fade fast.

Then I tried a set of PBR Metal Masters.  These pads are designed for much heavier use.  I never got them to fade, but the cold stopping was not very good at all.  One time while on the freeway during a long road-trip, where I hadn't touched the brakes in a while and they were COLD, all the traffic in front of me came to really quick STOP.  I hit the brakes and found I had very little braking power.  I mashed the brake pedal using every bit of strength I had and I baaaaaarely stopped just a few inches from the car in front.
The Metal Masters went in the TRASH as soon as I got home!


MINTEX BECAME MY FAVORITE
Many years ago a fellow 240 owner, Clay Dewan, suggested Mintex (red box) pads in the photo below.  I was a skeptic, because they were inexpensive and I didn't know the brand.  I tried a set and absolutely fell in love with them.  They had great cold and WET stopping. They had excellent braking power when really hot too.  I used Mintex pads for several years and also during a number of track days. I even boiled my brake fluid at the track once and then later changed to higher-temp DOT 4 brake fluid. Even so, the Mintex pads never failed me.  I highly recommend them for your 240 if you can find them.  These used to be widely available in the U.S.A, but now It seems these pads are either no longer available or hard to find (at least for a 240).


UPDATE FOR August 2023: Mintex ceramic FRONT pads now seem to be available for 240 at Swedish Car Parts:
swedishcarparts.com/parts/brake-pads

Nowadays the internet can find almost anything. Here's a list of performance 240 brake pads, but I cannot offer any personal recommendations.
carid.com/1984-240-performance-brake-pads

BNE Dynamics (Kaplhenke Racing) now offers HAWK performance pads for Volvo 240. I have not tried these, but I suspect they're worth a try.
https://www.bneshop.com/collections/240

Here's a good discussion thread on performance brakes pads for 240s:
 https://forums.tbforums.com/showthread.php?t=339806


STOCK 240 BRAKE SPECS
Late Volvo 240 FRONT 4-piston CALIPERS
     Front caliper: 38 mm pistons (four pistons), 1976-1993 using Girling versions.
 Left caliper
PN 1273430, 1330306, for VENTILATED rotor.
 Right caliper PN 1273431, 1330307, for VENTILATED rotor.

       FRONT (late 240): 24 mm (0.945 inch) thick VENTILATED rotor. 263 mm (10.35 inches) diameter. PN 1228153, 1359131, 270739-6.



Early Volvo 240 4-piston FRONT Calipers
Be aware of early version 240 calipers made for thinner SOLID, non-ventilated front rotors. These came in some 1983 and earlier 240s and different calipers were used.

 
Left caliper PN 1221957, 1330303, for NON-VENTILATED rotor.
 Right caliper
PN 1221958, 1330304, for NON-VENTILATED rotor.        
Brake line ports are all M10 x 1.0 bubble flare (European).

FRONT (early 240): 14.3 mm (0.563 inch) thick NON-VENTILATED rotor. 263 mm (10.35 inch) diameter. PN 1228942, 270737-0.



  Volvo 240 2-piston REAR Calipers (all rears were solid):
Rear caliper: 38 mm pistons (two pistons). Manufactured by ATE or GIRLING.
 Left caliper GIRLING
PN 1229547, 1330308.
Right caliper GIRLING
PN 1229548, 1330309.
Left caliper ATE
PN 1229551.
Right caliper ATE
PN 1229552.
    
Brake line ports are all M10 x 1.0 bubble flare (European).

ATE versus GIRLING
REAR Caliper Differences


ATE brake calipers will always have the "CROSS style" metal spring retainer.
GIRLING calipers will always have the thin METAL WIRE spring clips.
 

Volvo 240 REAR Brake Rotors (all years):
   REAR:  9.6 mm (0.378 inch) thick rotor. 281 mm (11.06 inches) diameter. PN 1205782, 270736-2.


How to Replace the Front Brake Pads, Rotors, Calipers
https://www.youtube.com/watch?v=KWhAcHQAk_E


Volvo 240 Master Cylinder Info:
Dual circuit braking systems (AKA: dual or tandem master cylinders): A tandem MC has been required on all cars in the U.S. since 1967.
In 1966 Volvo introduced their new triangle-split dual circuit brake system (diagram shown HERE).
Beginning in 1975, Volvo introduced the new STEPPED BORE master cylinder.
More info on STEPPED BORE master cylinders Click HERE.

        BELOW MC: Non-ABS type. This MC has a STEPPED bore: 22.3 mm (0.878 inch) primary bore (REAR), 15.75 mm (0.62 inch) secondary bore (FRONT).
FRONT and REAR here refers to the master cylinder.  It does not refer to front or rear brakes.
The PRIMARY BORE is designated for the FRONT brake circuit.
     Beginning 1989: ABS type master cylinder: This has a STEPPED bore: 22.3 mm primary bore (REAR), 19 mm secondary bore (FRONT).
Brake line ports for all Volvo MCs are M10 x 1.0 bubble flare (European). More detail HERE.
 

 
More info on STEPPED BORE master cylinders Click HERE.

Volvo Master Cylinder Part Numbers:
     240 non-ABS Brake line ports on left PN 8111005-8.
   240 non-ABS Brake line ports on right PN 8111006-6.
240 with ABS PN 3530972, 8251131, 8602015.
Brake line ports are all M10 x 1.0 bubble flare (European). More detail HERE.

Volvo Vacuum Brake Servo Boosters:
This section is below the Master Cylinder section.
Click HERE for BRAKE BOOSTERS.

Volvo 240 Brake Pedal Ratio: About 4.3:1

The brake pedal ratio of 4.3 to 1 represents the leverage increase your brake pedal provides between the foot pad and the master cylinder pushrod. This measurement above was taken while my pedal box was in the car and I had to contort myself and dislocate all my limbs to get it. So it you have a brake pedal OUT OF THE CAR and can verify these measurements, please let me know.

As far as I'm aware, all 240s were equipped with power brakes. If a factory manual brake 240 ever existed, it would likely have been designed with a very different pedal ratio, possibly as high as 6 to 1 or 7 to 1. The brake pedal ratio can be altered if needed. Near the bottom of this page you can read about Dick Princes racing 240, which had an altered pedal ratio for using racing manual brakes (dual master cylinders with a balance bar).



 
Volvo 240 Brake Line Routing and Bleeding
Triangle-Split Dual Circuit Brake System (non-ABS) 1975-1989  (for ABS brakes CLICK HERE).



VIDEO: Volvo 240 Brake Bleed / Flush (non-ABS)
https://www.youtube.com/watch?v=fuvmLfaVnQo
PLEASE . . .
DON'T USE YOUR BRAKE PEDAL FOR THIS.

The above image is from Bleeding Brakes for Dummies and it suggests it's OK to use your brake pedal to push brake fluid through your lines when bleeding your brakes.
Advice based on MY experience:
1. Do NOT use your brake pedal to bleed your brakes unless you have absolutely no other choice (road-side emergencies, etc.).

2. If you must use your pedal, do not push it in any further than it would normally be pushed during normal braking.
This is because the cylinder seal can become damaged when pushed into a position not normally used because of corrosion that forms on the cylinder wall.

3. The 240 has a Triangle-Split Dual Circuit Brake System, which has a lot of lines to get air out of.
Often when using the pedal to push fluid, you cannot move fluid fast enough to evacuate all of the air that may be trapped in higher bends. This can result in frustrating and time-consuming repeated bleeds, over and over until getting all the air out.
GET ONE OF THESE


When it comes time to bleeding brake or hydraulic clutch lines, I highly recommend the Motive Power Bleeder.  I've used one for 20 years and it allows thorough DIY bleeding with no need for a helper.   
VIDEOS ON USING THIS ITEM:
https://www.youtube.com/watch?v=JWJIYeourjY


MORE Power Bleeder SEARCH QUERIES:

https://www.youtube.com/results?search_query=motive+power+bleeder



ABS BRAKES

The Volvo Anti-Lock Braking System (ABS), beginning in 1989 for a 240, was a three-channel system using a Bosch electronic control unit and hydraulic modulator to monitor and compare signals from three wheel speed sensors (one on each front wheel hub and one in the rear differential).
With ABS there is only ONE brake line for each front caliper, instead of two like on the earlier cars. 

ABS BRAKE LINE BLEEDING.




STEPPED BORE MASTER CYLINDERS
All 240's came with stepped bore master cylinders.
 
  A stepped bore means the rear (primary) bore has a larger piston than the front (secondary) bore. When using the factory Volvo triangle-split braking system, brake line pressures reportedly remain identical from either outlet port.
FRONT and REAR here refers to the master cylinder.  It does not refer to front or rear brakes.
The PRIMARY BORE is designated for the FRONT brake circuit.
 
Non-ABS Volvo 240 REAR bore: 22.3 mm
Non-ABS Volvo 240 FRONT bore: 15.75 mm

ABS Volvo 240 FRONT bore: 19 mm
ABS Volvo 240 REAR bore: 22.3 mm.


Normal Bore (non-Volvo) versus Stepped Bore

An explanation from Volvo:
By Ante Larsson; Lars Larsson, AB Volvo, 1975.
STEPPED BORE MASTER CYLINDER -- A WAY OF IMPROVING DUAL BRAKE SYSTEMS
Dual brake systems are required in motor vehicles in the United States. These systems increase the safety of motor vehicles by overcoming the loss of braking effect which occurs when a brake pipe or hose in a single-circuit system breaks. However, a disadvantage of the dual system is the extra pedal movement and increased pedal force which are required when one circuit has broken down. Since the maximum deceleration which can be obtained is dependent on the largest pedal force that the driver can produce, or the maximum friction force which can be exerted at the braked wheels, a deterioration in deceleration normally occurs when one circuit breaks down. A dual brake system which includes a tandem master cylinder was introduced on the Volvo 144 in 1966. This system still caused rather large pedal stroke losses when one circuit broke down, resulting in a feeling of unresiliency in the pedal. A new type of master cylinder was introduced on the Volvo 244 model for 1975. The function of this new cylinder is based on the use of two pistons, loosely connected with one another, and with different diameters, in one cylinder. When the brakes are applied with an intact system, the pressures in both circuits are the same. The pressure equalization necessary to obtain the same pressure in both circuits is achieved in the stepped bore master cylinder with a secondary piston, which floats within certain limits. The stepped bore master cylinder gives high brake fluid pressure with a moderate pedal force with one circuit out of function. It is probably most suitable when used with disc brake systems. With drum brakes, a good automatic adjusting device is needed.
Rept. No. SAE-750385 ; 1975 ; 8p
Presented at the the Automotive Engineering Congress and Exposition, Detroit, Mich., 24-28 Feb 1975.


Disassembling a Master Cylinder
https://www.youtube.com/watch?v=WYB4vOv7Iag


Disassembling or Rebuilding a Brake Caliper
Pretty good general video (non-Volvo).
https://www.youtube.com/watch?v=ULnBjRXnAiU

Pretty good video on disassembling a Volvo 240 front caliper. This person is discussing a modification of the caliper to change from dual circuit to single circuit front brakes.
https://www.youtube.com/watch?v=HHEqs4mdXE8

.

240 BRAKE BOOSTERS
Volvo 240 Vacuum Brake Servo Boosters:

10 inch GIRLING single diaphragm, black or yellow chromate, PN 1229928, 1272159, 3516654. 
Assist Ratio: 3.5:1 (Volvo Greenbook).
10 inch BENDIX DBA single diaphragm, galvanized gray, PN 1272159.  Assist
Ratio: 3.5:1 (Volvo Greenbook).
Note: The finishes or colors noted above have been found in Volvo literature, but this info has been found to NOT always be accurate.


8 inch BENDIX DBA dual or "tandem" diaphragm, PN 1229336 (unpainted).  Assist Ratio: 4:1 (Volvo Greenbook).
8 inch GIRLING dual or "tandem" diaphragm, black, PN 1229493
.  Assist Ratio: 4:1 (Volvo Greenbook).
Note: The finishes or colors noted above have been found in Volvo literature, but this info has been found to NOT always be accurate.


Choosing a DUAL Diaphragm or SINGLE Diaphragm Booster.
Most 240s came with dual diaphragm boosters. I think there was a period where some models in the 1970s came with a single diaphragm booster, possibly for carburetor models. The dual diaphragm booster offers more assist, but the single diaphragm can move the master cylinder rearward a few inches if you need extra clearance for a larger intake manifold. More assist can be helpful for an engine that has lower manifold vacuum, such as a B21FT with 7.5:1 compression ratio, or a larger camshaft. When Volvo calculated the assist ratio of 3.5:1 or 4:1, it means that with 3.5:1 ratio, if you push the brake pedal with 100 lb. of force, the booster translates that to 350 lbs. And with 4:1 ratio it translates it to 400 lbs.

ASSIST RATIO
The Assist Ratio is said to be partly derived from the valve assembly inside the booster combined with the size or area of the vacuum diaphragm. I don't have a good understanding of the valve design, but I can offer an explanation how assist is relative to engine vacuum combined with the DIAPHRAGM AREA. The larger the diaphragm, the more vacuum assist will be available. A dual diaphragm can double that assist, but since most dual diaphragm boosters are smaller in diameter, it comes down to the total combined diaphragm area. Mathematically speaking, thr area of a circle if calculated as: Area = pi r. Putting this into relative booster sizes can help.
Example: A 10 inch diameter single diaphragm booster has a diaphragm area of 78.5 square inches
.
Compared to a more common 8 inch dual diaphragm, which has 100.54 square inches.

So when considering diaphragm assist, the 8 inch dual diaphragm should offer about 28% more assist than a 10 inch single diaphragm.



TESTING YOUR BOOSTER
There are a lot of "TIPS" on-line for testing a booster. Most of them discuss testing by pressing the brake pedal.  A REAL test of a booster is done by checking to see if it actually holds vacuum. 

This is done by using a hand-held vacuum pump or an electric AC vacuum pump. The below video offers a quick summary.  It's not complicated. A good booster should hold a steady vacuum for a good long time. Older ones can slowly leak past the edges of the diaphragm or through the valve inside the booster. When testing, you'll find that a dual diaphragm booster will take longer to pull a vacuum than a single diaphragm. 
https://www.youtube.com/watch?v=h0Z4WPqhLqc



INSTALLATION TIP
Installing a New Booster?  Pushrod Length Verification and Adjustment
Dual diaphragm type shown below.

When I installed a new booster in my 240, I took to a few photos below of how I checked the pushrod length. I did this because I was installing a new NON-genuine Volvo part and I found the the pushrod end lock-nut had not been tightened. So I wanted to make sure the pushrod end length was set correctly. 
 

The pushrod end is this part above which is threaded into the front thrust rod in the booster. It pushes into the back of your master cylinder. These two photos above are from an original Volvo booster. I removed this pushrod end from an old Volvo booster and I keep it in my toolbox.

  Here's the pushrod on the new NON-Volvo booster I bought. The pushrod was different. The thread pitch and the lock-nut were not the same.


This is a back of the master cylinder. The flat back of this flange bolts to the booster face. The round end will go into the booster about 16 mm.


Using my spare pushrod end, I inserted it into the back of the master cylinder and I measured how much of it went in. I measured between 17 and 18 mm.


So then I made sure to set the push-rod end length so that is was protruding about 1 to 2 mm from the booster.
The goal is to close any gap and to remove any play between the booster and master cylinder when the pedal is at rest.


If you've been wondering how a vacuum booster works, here's a short animation video.
https://www.youtube.com/watch?v=wbTUvp-tD5M





240 BRAKE LINES
Brake lines are a mystery for many DIY car enthusiasts, so I thought it would be a good idea to make a section about DEALING WITH 240 BRAKE LINES.

FIRST PROBLEM:
Due to the age of your car, your brake fittings are probably a bit crusty. There may be some corrosion and they may be very tight. 
Those original brake line "nuts" use an 11 mm wrench.  If you try to use a simple open end wrench on them or maybe some poor fitting adjustable wrench, you're asking for trouble.  These fittings are made from soft brass and it's very, very easy to accidentally round off the corners on them.


Buy yourself some line wrenches,
or at least buy one
11 mm line wrench. Sometimes called a FLARE NUT wrench. 


Then BEFORE you use your new wrench, look closely at it.
You'll probably have one like the first or second wrench shown ABOVE.  Notice these wrenches have a bit of a rounded shoulder where the wrench surface touches the fitting nut surface. That rounded shoulder will probably cause you some trouble if the nuts are extra tight, because it prevents the wrench from sliding fully on and grabbing as much of the nut flat surface as possible.
I MODIFIED the BOTTOM wrench above. 
I used my bench grinder to grind the surface face down, flattening the shoulder on both sides.

The reason for this grinding will be easy to understand. 

In many of these circumstances you're going to have only one chance to grip the brake line nut well enough to actually crack it loose.  Rounding off the corners is so easy to do, especially if that nut has never been loosened before. If you round off the corners, you may be out of luck you'll have to cut off the line and then use a socket or locking pliers to remove the nut.

Grinding the wrench flat like I did will give you a small extra bit of gripping surface between the wrench and the nut.

In 2024 ProjectFarm released a pretty comprehensive video on testing different brand line wrenches.
https://www.youtube.com/watch?v=xlRuGboPIg8



  NEXT PROBLEM:
Looking at this photo BELOW,
you need to get that wrench to slide onto as much of that nut as possible.  If you only get the wrench partially on the edge of the nut, then the corners are going to round off and you're done. 
On this fitting shown below there is a small sheet metal retaining clip.  And  you can see what's left of one of those clips in my pliers. Those clips can interfere with you getting your wrench onto the fitting nut far enough to NOT round off those corners. So if you think your fittings are probably going to be stubborn, you can sacrifice those metal clips if necessary.  They're not easy to rip off, but you can break them with some force and wiggling back and forth. 

The fitting nut on the flexible hose going upward should be held by you with an open end wrench to keep it steady.  It will probably be 14 mm.
 

Or you can also do what I did in this photo below.
If you look closely you can see I just bent the wings of the clip outward a little.  That moved it out of the way so that it would no longer interfere with the wrench sliding ALL THE WAY onto the nut.

If you destroy your metal clips and you're not sure how to secure the brake lines when reassembling, that's what zip ties were made for.  In either circumstance it's always a good idea to look closely at your new or re-assembled brake lines and make sure there are no chances for a line to rub or vibrate against another hard surface.  I've seen brake lines vibrate enough to chaff a hole in only a few thousand miles, so again, ZIP TIES are your friend.




If you want to totally geek out on which brand line wrench is best, here's a detailed video on testing TEN different ones.
https://www.youtube.com/watch?v=kkCIjl5aEoA





 
USING PRE-ASSEMBLED BRAKE LINES


If you don't have the skills or tools to create and flare your own new brake lines, you can usually get by with pre-made ones. 
If you need any new pre-assembled brake lines, Belmetric has a selection in the correct fitting size for Volvo with a variety of lengths from 10 inches to 120 inches.

You may use metric 4.75 mm or 3/16 inch brake lines for any and all Volvo 240 applications.  Original Volvo lines are 4.75 mm, but 3/16 inch equals 4.76 mm, so there's no difference.
 https://www.belmetric.com/475mm-brake-line-with-ends-c-17_186_1168/

PROPER BRAKE FITTINGS FOR A VOLVO
Don't confuse Asian fittings with Volvo fittings.

The standard brake fitting size for Volvo is 10 x 1.0 mm (ISO or DIN) Bubble Flare - "European." 
The "European" part is important, because there's a Japanese/Asian version of this size fitting (with a double flare) which will NOT fit your Volvo.
Most (non-Volvo) brake lines use a DOUBLE FLARE (AKA: Inverted Flare).
All VOLVOS use an ISO/DIN BUBBLE FLARE ONLY.





BRAKE LINE UNIONS


If by chance you find a need to join two pre-assembled lines together, you can safely use a BRAKE UNION.

This might be needed because the pre-made lines you bought aren't long enough as one piece. That's OK.
Brake Union fittings are available in brass or steel in the correct 10 x 1.0 mm Bubble Flare (European).
Belmetric offers them: https://www.belmetric.com/bubble-flare-c-17_564_1107_1108/.

SHOULD YOU USE BRASS OR STEEL FITTINGS AND LINES?
Brass fittings and lines have an advantage against corrosion. Brass doesn't rust, but brass is not as strong, so stripping threads or rounding off corners is easier.
Steel fittings and lines are strong, but can rust. Good steel fittings will come with corrosion resistant plating, but they can still rust over time if the environment is corrosive.



DIY F
LARING AND BENDING NEW BRAKE LINES

You may use metric 4.75 mm or 3/16 inch brake lines for all Volvo 240 applications.  Original Volvo lines are 4.75 mm, but 3/16 inch equals 4.76 mm. So no difference.
If you're a beginner, here's a good video to start with.
https://www.youtube.com/watch?v=_Tm6N5l69_c



This video is a review of the TGR brake line flaring tool. This is the tool I use and it works very well.
https://youtu.be/QmK2h8FXEoQ

Tools like these can be available at different prices depending on how much it can do. This tool in the video is on the lower end of the price scale. It's available on Amazon here:
https://www.amazon.com/TGR-Professional-Brake-Flaring-Degree/dp/B01HOXH242/ref=sr_1_1_sspa
This tool can handle 3/16, 1/4, 5/16, and 3/8 tubing. (Volvos use 3/16"). Copper or steel brake tubing. It will create Single Flares, Bubble Flares, and Double Flares (Volvos use Bubble Flares).


FLEXIBLE STAINLESS BRAIDED BRAKE HOSES
Braided stainless brake lines can improve brake system feel and pedal response because the Teflon inner core will not expand under pressure like rubber lines can. These can be found for a 240 from several sources.
https://yoshifab.com/store/240-rear-ptfe-brake-line.html
https://www.ipdusa.com/products/5123/Stainless

Most people buy pre-made flexible brake hoses, but if you have ever thought about making your own or seeing how they're made, here's a video below.

Making Up Stainless Steel Braided Brake Hoses
https://www.youtube.com/watch?v=5tdsgZ-KfWI

.
FRONT STRUT BRAKE LINE BRACKET

If you agree with me that there needs to be a better way to secure your brake lines to the front strut, then you may like the below alternative.
 

I ordered a pair of these brackets from BNE Dynamics (Kaplhenke Racing):
https://www.bneshop.com/collections/240/products/240-split-brake-line-bracket


I had my struts off of the car when I did this.
My cordless reciprocal saw took the old brackets off in just a few seconds.  Then a bit of grinding with a bench grinder smoothed them nicely. 
Then some new paint and the new Kaplhenke brackets went on.
    
My car is happier now.





240 BIG BRAKES: Chapter 1
Front R-BRAKE Installation

I began this project in December 2003 when I first purchased a set of new R (BREMBO) front calipers.
These calipers were made for the 2004-07 S60R and V70R. 
For this project FRONT CALIPERS ONLY were fitted to my car. 
For installation of Front AND Rear R-Brakes - CLICK HERE.

These calipers were new and this kind of adaptation had not been done yet. My original plan was to design a custom caliper bracket to fit these calipers onto the front of my 245.  Before I got very far, I received an email from Travis Kijowski of Strictly Volvo Racing (SVR) in Maryland. Coincidentally, he was already in the process of developing an aluminum bracket for these calipers to fit a 240 strut housing, which he would later adapt for his 940.   

I originally planned to have a 2-piece rotor set made using Wilwood hats and rotors, but when I found out about the SVR brackets, which could use the stock S60R rotors, and the rotors would bolt right up to the 240 with no modifications, I put off the idea of custom rotors for a while and bought a set of S60R rotors to save some time and money.

Keep in mind that S60R, V70R rotors mounted on a 240 will push the outer rotor surface about 1/2 inch further outward than the factory original rotor. This means your caliper will be more outboard and this should be considered when planning for your wheels if the clearance is close.
        

I completed this project in March 2004 using caliper mounts from SVR and it turned out to be one of the best mods ever.

2021 Update NOTE: 240 R Brake Adapter Kits (FRONT AND REAR), available from STS Machining.
 https://www.stsmachininginc.com/240-big-brakes-s60r-v70r

These R calipers are LUG MOUNTED
 

Factory R Calipers MUST BE SWAPPED LEFT TO RIGHT when installed on a 240.
The below LEFT image shows how these calipers are normally mounted on an S60R, V70R, FORWARD of the center hub.
The below RIGHT image shows how these calipers are mounted on a 240, BEHIND the center hub.

When installing factory R calipers on a 240, the rotor direction needs to be reversed in relation to the caliper, which means the small leading piston will become the following piston. This may not be an ideal setup if you're worried about that, but it's necessary unless you can re-work the calipers so the bleed ports are changed to the opposite ends.

AFTERMARKET CALIPER NOTE:

As of 2021 there are new aftermarket R calipers available, which have bleed valves on BOTH ENDS.
This means that these calipers can be used on the LEFT OR RIGHT sides and you'll always have a bleed valve at the top

The S60R front caliper is an aluminum 4-piston type made for Volvo by Brembo. 
The caliper weighs 7 lbs. 6 oz. (about 3.3 kg). They are different on the right versus left side.

This caliper has 4 pistons, which can be said to have staggered or offset piston sizes. Two pistons are 42 mm diameter and two are 38 mm diameter.


The below video offers a good explanation of why a caliper can have two different piston sizes.
How MOTORSPORT Brakes Work | Brake Caliper Setup
https://www.youtube.com/watch?v=HfTkIOgRig8
 

The front R calipers will use MORE FLUID VOLUME that stock 240 brakes, but just HOW MUCH more?
240 calipers FRONT: (38 mm x 4) x2 (right+left) equals 9072 mm total piston area.
R calipers FRONT: (42 mm x2 plus 38 mm x 2) x2 (right+left) equals 10090 mm total piston area.
  So the FRONT R calipers combined have 11.2% more area.

My conclusion: Upgrading to a master cylinder with more volume or a larger bore is not necessary.

This installation below in my 240 used the STOCK 240 (non-ABS) master cylinder.
The front rotor (also made by Brembo) is 13 inches (330.2 mm) x 1.25 inch (32 mm). 
These are quite a bit larger than the original 10 inch brakes on the 240.  The rotor weighs approximately 20 lbs (about 9 kg). 
I had the slots shown below custom machined at the cost of about $25 per rotor. 

(BELOW PHOTOS) The first photo below is the original 240 brake (RIGHT SIDE)... stock rotors (except for custom drilling/slotting).  
The second photo shows the R caliper and rotor after installation on a 240.   

 

The natural finish aluminum bracket below is the first prototype bracket used to test and confirm fit. It allowed the R calipers to bolt to the 240 struts tubes with no other mods.  The later versions were black anodized with laser-etched "SVR." 
These brackets weighed in at 15 oz. each (about 425 grams).  


UPDATE November 2008:  These brackets became no longer available from the above source. 
New sources have come along and may be found in my Cool Volvo Products Page.

Lots of detailed info has now been written by other people about this conversion over years and can be found in the Turbobricks Forum (https://forums.turbobricks.com/) and at the below links specifically (among others):  
https://forums.turbobricks.com/showthread.php?t=22183
https://forums.turbobricks.com/showthread.php?t=22070
https://forums.turbobricks.com/showthread.php?t=17562
https://forums.turbobricks.com/showthread.php?t=20624

The brackets from SVR were designed to allow the R caliper to be mounted in almost the same place as the stock caliper.   You can see in this pic how the R caliper is moved outward (away from the strut tube).  This was necessary so it would correctly fit the position of the R rotor, which places the brake surface further outward than the 240 rotor. 

To put this in perspective, when measuring from the outer brake surface of the rotor, the R rotor will be about 5/8 inch (about 16 mm) more outward than a stock 240 rotor.  
The outside face of the larger R caliper will be about 24mm (just under an inch) FURTHER OUTWARD than a stock 240 caliper, so you should consider this when determining possible interference with wheels.

The stock sheet metal brake backing plates were useless for this upgrade and were removed.

Notice that you only need ONE brake line per wheel instead of two brake lines as my car originally had.

FRONT R BRAKE PARTS LIST:
Front R CALIPERS. Volvo PN 8602682 (right) and PN 8602683 (left)
  Front R ROTORS. Volvo PN 30645222 (same left or right).  The grooves in mine were custom machined.
The SPRING CLIPS/RETAINERS are Volvo PN 30645137 (2 sets required).
VOLVO front brake pads are PN 30645135 or 30748957. I opted for EBC GREEN STUFF pads on front instead, PN DP21210

BOLTS USED FOR THIS CONVERSION:
Minimum of Grade 10.9 hex head or 12.9 black socket head is recommended.
Metric Bolt 12 x 1.75 mm x 40 mm (4 required)
Metric Bolt 12 x 1.75 mm x 60 mm (4 required)
Hardened 12 mm washers recommended (8 needed)

Brake Junction Block Plugs, Volvo PN 1387506 or any M10 x 1.0 mm (ISO or DIN) Bubble Flare - "European." (2 required).
Correct plugs can also be found at: https://www.belmetric.com/bubble-flare-c-17_564_1107_1108/

You'll notice two new metal hard brake lines in the below picture (about 12 inches long). 
These pre-made hard lines were used to replace the original copper hard lines going from the calipers to the flexible lines (I already had stainless front flex lines that I bought from iPd years before, so I used one of those for ea
ch side). 

The old original 240 hard lines can be re-use
d, but I found the old original brass end fittings often become damaged when removed if they're tight, so I decided to buy new ones. 
FCP Groton
used to carry them (PN AA0320), but they seem to no longer have them.
A variety of lengths of pre-made correct hard lines can still be found at Belmetric: https://www.belmetric.com/475mm-brake-line-with-ends-c-17_186_1168/



NOTE Regarding Brake Shims and Brake Squeal:
Some people have had trouble with brake squeal with these front calipers. Many have complained that they find it impossible to locate brake pad shims, like those shown above. The above shims came with the factory pads I bought back in 2004.
I used EBC Green Stuff pads with the shown shims. I never had brake squeal noise.
But for those who need help, this info below may help.

Back in 2004 when I was researching these calipers and available brake pads, Brembo listed this caliper as their type "B62" or "62" family.
I found that the same Brembo B62 FRONT calipers and pads were used in some other cars.
2004 Subaru Impreza STI (2004-17)
2004 Mitsubishi Evo (2003-15)
2004 Alfa Romeo (I can't recall the model, but I recall it was available in Europe and NOT in the U.S.).
And a few others.

So there may be BRAKE PAD SHIMS available for these other cars which will work, such as these for the STI:
https://www.vividracing.com/girodisc-front-shims


HAWK BRAKE PAD DIAGRAM (FRONT) for Brembo B62 Caliper.

 
And there's MORE. I found the below FRONT PAD image in an EBC Racing Pad catalog. It lists more uses of the Brembo B62 caliper:
https://ebcbrakes.com//EBC_RACING_PROD_BRO_USA.pdf




Also Volvo had a campaign at one time to combat brake squeal complaints in the R calipers. This image below is Volvo PN 30748514 Anti-Vibration Damper Set.
These are made to mount between the front caliper and mounting bolt heads. I have no idea if they worked.



If you also need to find alternative vehicles using the S60R REAR pads, this image below is used by Hawk brake pads sites for the S60R REAR pads.
The calipers used by Volvo on the rear were Brembo B11.

So it appears there are some Lotus, Jaguar, Mustang and Viper models using the same Brembo B11 rear calipers calipers.


HAWK BRAKE PAD DIAGRAM (REAR) for Brembo B11 caliper.

Here are the S60R REAR pads from the EBC Racing Pad catalog, listing more cars using the B11.




BRAKE JUNCTION ROUTING
for Front R-Brakes


First let's look at the ORIGINAL FACTORY 240 SETUP:
The 240 non-ABS brake junction block (manifold) shown here has 8 ports. This first photo below illustrates the original 240 brake line
configuration when using the original 240 front calipers in my '84 240, which originally used two brake lines per front caliperThe front Brembo R calipers use only one line per caliper.  For this conversion, two of the front caliper ports on the junction block (manifold) will need to be plugged.
 

 MODIFIED PLUMBING. ALTERNATE 1:
This is how I originally made this work back in 2004 when I installed the front 'R' brakes on my 1984 245. 

  I
simply removed one front brake line from the right side and one from the left. I then PLUGGED the two empty holes.
 

This method worked fine for years. I did receive some grief from a few 240 enthusiasts who felt it was unsafe. They felt that if one front caliper suddenly lost pressure, hitting the brakes would shoot the car off to one side out of control and it would be a disaster.  I suppose it's possible, so use caution and you're own judgement.

NOTE: Jacob (who installed Porsche Cayenne calipers) also used and recommended this method in his brake instructions. 
As far as I know so far, no one has done it differently for an R conversion (except for full proportioning valve additions) and this has been done MANY TIMES over the years.

ALTERNATE 1A (photo not shown of this one): 
If you're OK with Alternate 1, but are shaking in your booties about the potential problem mentioned above, this may be a solution.  This method uses the same configuration shown in Alternate 1, except for one change.  As shown in Alternate 3, you would remove the inner piston assembly. This will convert the two-chamber junction block into a one-chamber junction block.  Any fear of the car shooting off left or right should be gone now.  Be aware that if you lose pressure with this configuration, you lose all brakes.  So choose your poison. 
I have not tried this method and to my knowledge no one else has either.

Plastic Sender Note:
 If you remove the inner piston, I think it might be a good idea to remove the plastic sender and plug that hole with a metal plug (M12 x 1.0 thread).  The internal pressures may be too much for the plastic sender after removing that inner piston assembly. Not sure. Just saying to think about it

More on this is discussed a little below in the "Plastic Sender" section.


ALTERNATE 2: 
This is a method suggested by a someone who was concerned about Alternate 1.  If you choose to do it this way, you will need to either bend the existing brake lines to fit (if possible) or make new ones.  This method is very similar to how the ABS 240 was plumbed. 

The safety aspect of this method is as follows:  If pressure is lost somewhere, then you will lose either front brakes or rear brakes, but not all of them at once.

In September 2022 I received an email from Steven B. in Oslo, Norway. He mentioned that he had originally tried Alternate 1 for his front R brake installation and had some intermittent trouble. He was using a standard master cylinder, brake junction manifold and rear brake reduction valves from a 1979 265. The source of the trouble remained a mystery for a while. He believed the trouble seemed to be related to the piston inside the junction manifold, which he believed may have been moving to one side during repeated brake use. This was slowly causing a pressure imbalance, which would happen after using the brakes a number of times. Soon the brakes would begin pulling to the left after using the brakes through the day.

This issue would resolve by itself if the car sat unused overnight, but then would gradually repeat when brakes were used repeatedly. He could find no defect in any part.  Steven decided to try Alternate 2 configuration and the problem was resolved.

Steven also said in order to get upgraded brakes approved in Norway, a DUAL SYSTEM must be retained. Using Alternate 2 was sufficient for that approval.  


I would certainly appreciate some feedback if you have done an R brake conversion.  What method did you use?
CONTACT


ALTERNATE 3:
This is a proposal for those of you who would choose Alternate 2, but would like to eliminate the internal piston. 

I have not tried this method and to my knowledge no one else has either.

That inner piston separates the two chambers, but is designed to freely move forward or rearward depending on brake pressure differentials.  By removing the piston, the junction block is converted to a one-chamber block, instead of two.  Be aware that having a one-chamber junction block means that if any part of the brake system looses pressure, then all of it will. 


Plastic Sender Info:
If you remove the inner piston, I think it might be a good idea to eliminate the plastic sender.  There's a lot of pressure in there and I don't know if trusting a plastic threaded sender is the best idea.  The thread for this port is M12 x 1.0.  There are fittings available with M12 x 1.0 thread, but all I have found so far are JIC or AN fittings with a flared sealing end.  If you look under that white plastic piece inside the port, it's just a flat bottom with a small hole in the center, so a flared fitting will not seal there. 

There is, however, a chamfer for an o-ring, seen below, which is what the factory sender uses to seal.
 
So I think there is a very good chance of creating a seal using an M12 x 1.0 o-ring plug, such as this: https://www.onehydraulics.com/products/9030m-12x1-0.
Or PN 9151K245 from McMaster Carr, which was used successfully in this thread: https://forums.turbobricks.com/showthread.php?t=362998

If you do something l
ike this with your project, please email me. I'd like to know.
CONTACT

ALTERNATE JUNCTION BLOCK (Later BRAKE LINE MANIFOLD)
 
If you want a brake junction block (manifold) without a warning sender and without an inner piston, look for Volvo PN 3540084 from a 1991 240 (may be no longer available)
This manifold It will operate as two separate junction blocks with no shared internal port.



Another Alternate (custom)

If the above VOLVO junction block is not found, then there's a way to use two existing non-Volvo junction blocks as shown in this Turbobricks discussion below. These junction blocks are custom made for Nissan cars and are available from us.gktech.com/4-way-brake-union. These are specially made so that they correctly fit the European bubble flare fittings used in a Volvo.
turbobricks.com/373513/ (April 2024)


WILWOOD ADJUSTABLE PROPORTIONING VALVE
You may want to consider re-configuring your brake lines to use a proportioning valve like this one. It's a much bigger step and will require you to install mostly new brake lines. 
You can read about one of these installed on a 240 here at https://www.240turbo.com/volvo240bigbrakes.html#proportioning




WHEEL SIZE IS CRITICAL with bigger brakes:
When planning an upgrade
like the front R calipers, it is very important to carefully consider the need for larger wheels AND more room to the outside of the original brakes.  As far as wheel diameter, if you use these 13 inch rotors, there are some 17 inch wheels that still will not clear.  The wheel shown in these pics are 18 inch. 

So far I know the 17 inch Volvo R wheels will clear just fine and I have been told the Volvo Tethys also. Both are FWD type wheels and will need custom spacers to fit a 240 properly.

The popular EIKER (Polaris replica) is 17 inches and WILL NOT FIT because the caliper hits the inner wheel barrel.

The outside surface of the new, larger R caliper will be further outboard (in the direction of the wheel spokes).  My measurements show them to be about 24 mm further outboard when compared to the stock 240 caliper.  So if your wheel spokes are already close to your original front calipers, you will either need new wheels or some wheel spacers to move them outward.  Many more discussions from others who have worked out this installation can be found in the Turbobricks forum.

FRONT/REAR BRAKE BIAS

For braking to be effective when you get near the limit, you need a pretty good balance between the front and rear.  If any brakes begin to prematurely lock up, it is preferred that the front brakes lock just slightly before the rear brakes.  When I tested the front R caliper installation initially with no adjustments or changes to the front/rear bias (which included a track day at Thunderhill Raceway in May 2004),  I found the front brakes to have a little too much strength and would easily lock if I wasn't careful.  This required some concentration and discipline at track speeds.  I found if I was gentle on the pedal I could prevent it, but still it needed to be fixed.  For a better balanced setup out of the box, I suppose anti-lock brakes might work nice at leveling things, but adding ABS to my 240 wasn't an option. 

If I were to use an adjustable proportioning valve, the imbalance could have been solved with an easy adjustment. My first thought was to see what would happen if I removed the rear brake reduction valves (to increase rear brake bias). If that wasn't enough of a fix, then I could install an adjustable proportioning valve.  So I did the first step and removed the rear reduction valves. 

After the reduction valves were removed, I needed some way to re-connect the brake lines and found that a standard early 1980's 240 junction block (shown in photo) worked perfectly in place of the reduction valves. I had an extra one on-hand.  It fit like it could have been made to go there.  Four of the open ports on the block needed to be plugged (so four more brass plugs were needed).
Alternatively, a brake union setup would have worked.  More info about that is in the Brake Line Section.

After testing the brakes with the rear reduction valves removed, I discovered the front/rear bias was nearly perfect for a wagon.  Much better than expected.   I then had a very nice front/rear balance which took full advantage of the improved brake system.  Much stronger front brakes (because they're big) and stronger rear brakes also (since removing the reduction valves).

So now we know this can work for a 245.  What about a 242? 
....After Doug Kauer (Hank Sporpio) did his R brake install on his 242, he then tried this method above and found the result to be perfect for his car: https://forums.turbobricks.com/showthread.php?t=22183.

Yes, many mods like these can be considered amateur, but many Volvo owners have greatly improved the performance of their cars over the years through such experiments.  This isn't the end-all solution and it might not be for you, but for the money, it was one of the best modifications I have ever done to any Volvo.  I want to thank Travis Kijowski at Strictly Volvo Racing for designing and producing the caliper brackets.  They turned out very nice. 

If you do a mod like this (or do it differently), I would like to hear about your results.


Experimentation is the key to improving modifications.
Here is an R caliper installation that was done a little differently and the results.

-from Matt Dupuis (added 07-16-06)
Here's some feedback on my conversion, and what I've done differently than (I think) everyone else:

The piston dimensions on the S60R calipers when mounted on a P2 car (S60R) are 34 mm for the leading piston and 38 mm for the trailing one.  For a staggered piston design to work as designed, the trailing piston must always be larger than the leading piston.  This is done on calipers with long pads to keep the pad twist under control and to keep the pad wear (and heat) even across the length of the pad.

It occurred to me later that the P2 chassis has the calipers mounted in front of the axle centerline, and that the leading (smaller) pistons would be on the top, and on the same end of the caliper as the bleed nipples.  When rotating them around to the rear of the axle centerline, as on the 240 chassis, the smaller piston would remain the leading piston.  This would be the correct way to installed them, however it places the bleed nipples pointing straight down.  Furthermore, the high pressure line, as it comes out the caliper, would also be angled down, making it difficult to route the line away from the suspension control arm.

I pondered these problems when I was doing my installation, and attempted removing of the blanking plugs from the trailing side of the caliper to move the bleed nipples to that side so they'd be pointing up.  They would NOT come out.  I tried heat, I tried chemicals (thread unlocker), and I tried force.  Eventually I stripped a couple of the plugs' socket hexes (not to mention the paint from around one of the plugs with my propane torch), so I gave up trying to move them.

I came to the conclusion that I'm only going to need to bleed these brakes once or twice, so I might as well remove the calipers and hang them "upside down" from the struts to bleed them.  I shoved a piece of metal between the pads to keep them from compressing, and bungee'd them to the spring, and they bled out just perfectly.

As far as the brake hose issue, I solved this by using a regular 240 hose and hose-to-caliper hardline.  The hardline threads into the caliper properly, and allows one to quickly bend upwards and clamp to the strut (being removable is necessary, so the caliper can be removed and bled again if needed).

And to my pleasure, these calipers fit just fine behind a Volvo Tethys wheel when using a 25mm spacer.  They're not very visible back there behind all those spokes, but they fit just fine.

I used Hawk pads for an Subaru STi as Hawk doesn't list them for the R, or at least they didn't when I bought the pads (The STi Brembo caliper shares the pad dimensions with these calipers).   I'm not sure if I'd use them again - they squeal when lightly applied and the dust is pretty dark, and on the Tethys the dust accumulates quite quickly. 

So far they're the most confidence-inspiring brakes I've ever driven.  I'm not 100% happy with the balance yet - the fronts are too powerful, even though:
a) my car's not lowered;
b) my car's got a heavy V8 in the nose; and
c) I removed the rear brake limiting valves, but boy does the car stop! 
I do prefer a bit more rear bias, and I don't spend any time on a road course, so I imagine I'm not the utmost authority on brake setup, but I wish I had a bit stronger rear brakes.  Next step MIGHT be converting to different rear calipers... maybe Rs and vented rotors as well?


As a follow-up to Matt's submission above...
On the subject of Potential Uneven Pad Wear due to the offset piston sizes and reversed calipers....  I pulled and inspected my Green Stuff pads after a few years of use and found nothing that suggested they were wearing unevenly.  Also, of all the other people running R calipers in the wrong direction on 240's, so far I have heard of no abnormal or uneven pad wear.... just great braking!  Take this for whatever it's worth, but I suspect the issue is not a big one. 


And a side note regarding comments I have read about EBC Green Stuff pads after I bought them.  I read several forum posts supposedly written by  "experienced" people, who said the Green Stuff pads were "horrible" because they were not aggressive enough for the track, but too aggressive for the street.  I have found after a few years with these pads (with some very aggressive track days) that I completely disagree with their opinions.  These pads have worked great for me.  No squealing, great stopping when cold, no fading when hot, and very little dust!  And others have since reported that Hawk pads are horrible when they get a little wet.  I haven't seen this problem with EBC Green Stuff.  And Hawks, as it turns out, are considerably more expensive than EBC pads.  My considered opinion is that Green Stuff works fine in this combination.
- Dave B.



240 Front R BRAKES:
CHAPTER 2
2006 Update: Wilwood 2-piece front rotors were added to front R-Brakes.
 
I wanted to upgrade to a two piece Wilwood rotor assembly, so I had the above pictured 2-piece rotor set made up. 
It was done by Todd Cook at TCE Performance Products in Tempe, Arizona, http://tceperformanceproducts.com.

And since a custom hat/rotor combo means that I could alter the rotor offset (within limits of course), I decided it was time to move the rotors inward .500" (1/2 inch).  This would give me broader wheel options in the future.  This is where the modified caliper adapters below came into play.  I had the raised pads on the adapters shaved .500" (1/2 inch) where they meet the caliper.  The other areas you see where aluminum was removed were necessary to clear portions of the caliper body. 




You may compare the first photo below (original SVR caliper mount bracket) to the second one showing the modified SVR bracket in place, which moved the caliper inward 1/2 inch. 


Now you might ask... If I could move the calipers inward 1/2 inch, then why not move them in further?  As mentioned above, there are limits.  The limiting factor with the 240 is the steering arm, which is normally less than 1/2 inch from the stock rotor.  That's about where my new setup put the Wilwood rotor. 




240 R-Brakes FRONT and REAR
2021 NOTE: 240 R Brake Adapter Kits (FRONT AND REAR) are available in the U.S. from STS Machining.
 https://www.stsmachininginc.com/240-big-brakes-s60r-v70r

The below photos show a 240 Turbo owned by Aris from Greece. This car is featured in my Favorite Modified 240 Page HERE
It has been fitted with FRONT and REAR S60R (Brembo) calipers and rotors.
WHEEL SIZE: Aris uses 18 inch wheels with these brakes. These big brakes will normally require at least 17 inch wheels.
The FRONT rotor, made by Brembo, is 13 inches (330.2 mm) x 1.25 inch (32 mm). 
The REAR rotor, also made by Brembo, is 13 inches (330.2 mm) x 1.1 inch (28 mm).
 


Here are the rear calipers in place below. The rear dust shields needed some minor trimming near the top of the caliper.
 

Factory R Calipers MUST BE SWAPPED LEFT TO RIGHT when installed on a 240.

FRONT CALIPERS
The below LEFT image shows how these calipers are normally mounted on an S60R, V70R, FORWARD of the center hub.
The below RIGHT image shows how these calipers are mounted on a 240, BEHIND the center hub.

The R front caliper is an aluminum 4-piston type made for Volvo by Brembo.  The caliper weighs 7 lbs. 6 oz. (about 3.3 kg). They are different on the right versus left side.
The caliper has 4 pistons, which can be said to have staggered or offset piston sizes. Two pistons are 42 mm diameter and two are 38 mm diameter.


AFTERMARKET CALIPER NOTE:
There are new aftermarket FRONT and REAR calipers available (as of 2021) that have bleed valves on BOTH ENDS. This means that these calipers can be used on the LEFT OR RIGHT sides and you'll always have a bleed valve at the top.

REAR CALIPERS
The below LEFT image shows how these calipers are normally mounted on an S60R, V70R, FORWARD of the axle.
The below RIGHT image shows how these calipers are mounted on a 240, BEHIND the axle.

This caliper has 4 pistons. Two are 28 mm diameter and two are 30 mm diameter.
This configuration reverses the rotor direction in relation to the caliper,
which means the smaller piston, which used to be the leading piston, will become the following piston.

The FRONT rotor, also made by Brembo, is 13 inches (330.2 mm) x 1.25 inch (32 mm). 
The REAR rotor, also made by Brembo, is 13 inches (330.2 mm) x 1.1 inch (28 mm).



240 REAR PARKING BRAKE
The S60R rear brake rotor has no provision for an internal parking brake, like the 240 does. So the 240 parking brake function is retained by using the drum portion of a standard rear 240 rotor with the disc area machined off.


The 240 drum is installed. Then the new rotor is placed over the 240 drum. In the second photo below, the rear rotor is in place, along with a wheel adapter.  


Standard wheel stud length normally protrudes out about 25 mm.
The drum is about 5 mm thick, so adding the new rear rotor PLUS the 240 drum BEHIND IT will reduce the wheel stud length by about 5 mm.
 



MASTER CYLINDER
Aris installed this 740 master cylinder below in his 240. He reports that the brake pedal feel with front and rear R-brakes is very good and needs no improvement.

This is Volvo PN 1273243 or 1359693, 1986-88 740 without ABS, 1991 940 without ABS. This MC has a stepped bore very similar to the stock 240 MC (without ABS).
STEPPED bore REAR dimension: 22.225 mm (0.875 inch) primary bore
STEPPED bore FRONT dimension:, 15.875 mm (0.625 inch) secondary bore.
    M10 x 1.0 bubble flare (European) brake line ports. Rear port on right, front port on center front.

 
The front and rear R calipers will use MORE FLUID VOLUME that stock 240 brakes, but just HOW MUCH more?

240 caliper FRONT: (38 mm x 4) x2 (right+left) equals 4536 mm
area per caliper. 9072 mm total area.
240 caliper REAR:
(38 mm x 2) x2 (right+left) equals 2278 mm area per caliper. 4536 mm total area.

R caliper FRONT: (42 mm x2 plus 38 mm x 2) x2 (right+left) equals 5045 mm
area per caliper. 10090 mm total area.
R caliper REAR: (30 mm x2 plus 28 mm x2 rear) x2 (right+left) equals 2645 mm area per caliper. 5290 mm total area.
 So the FRONT R calipers combined have 11.2% more area than a 240.
The REAR R calipers combined have 16.6% more area.
Piston Diameter to Area Calculator: https://coolconversion.com/geometry/circle/area/

11.2% MORE AREA for FRONT?  16.6% MORE AREA for REAR?
This means that if you think you MUST use a bigger master cylinder with more volume, it may not need to larger at all.

If the brake system is divided up into one FRONT system and one REAR system (which you will see in the next section), then we can calculate the volume differences more accurately. If I were giving advise, I would tell you to try the 240 MC first (or the above 740 MC). If the MC seems too small (it would have too much pedal travel or it might be too easy for the brakes to grab too hard), then you can start looking for an alternative.  

LET'S TRY A HYPOTHETICAL EXAMPLE.
For this example, let's use the 240 MC. We'll use the REAR bore (22.3 mm) for the FRONT brakes only. A 22.3 mm piston has an area of 390.6 mm.
Then we'll assume the 240 MC FRONT bore (15.75 mm) feeds the REAR brakes only.
A 15.75 mm piston has an area of 194.8 mm.

Regarding Ford Mustang MC Recommendations:
I know that a number of people have recommended or installed a "Mustang master cylinder" for use with  this R brake (front and rear) conversion. There has been some confusion, because there are several Mustang master cylinders; 1994-95 Ford Mustang GT, 1993 Mustang SVT Cobra and 1994-95 Cobra MC, all of which have different piston bore sizes. Details on all three of these can be seen HERE.

If we can assume the Volvo 240 design engineers knew what they were doing, perhaps we can expect a good choice for a larger master cylinder to be somewhat PROPORTIONAL to the increase in the brake caliper volume size.
For this comparison below, I'll concentrate on the popular Mustang GT 27 mm master cylinder specs:

This MC has a piston size of 1.0625 inch (27 mm) for both front and rear. This MC has a piston area of 572.6 mm
x 2 = 1145.2 mm. The 240 MC with its stepped bore (22.3 and 15.75 mm) can be said to have an average bore of 19 mm (piston area of 390.6 mm + 194.8 mm = 585.4 mm). Using this info, this means a Mustang 27 mm MC with a piston area of 1145.2 mm appears really, really big in comparison (a 95.6% increase).

  BRAKE PEDAL RATIOS
The 1994-2004 Mustang brake pedal ratio appears to be about 4.5 to 1. Compare that to a 240, which is about 4.3 to 1. So the Mustang pedal seems to have a little more brake pedal leverage.


What if we divide this Mustang GT MC into FRONT and REAR circuits as if we're dividing it with a proportioning valve.
Each piston in a 27 mm Mustang GT MC has an area of 572.6 mm.
Feeding the FRONT brakes, I find that the Mustang MC appears to provide 46.6% more volume over the 22.4 mm 240 primary (rear) piston.
Feeding the REAR brakes, the Mustang MC seems to provide 93.9% more volume over the 15.75 mm 240 secondary (front) piston.
Keep in mind that much volume increase could make for a very hard pedal, which could require extra leg effort. 

So let's say for example we're going to try a smaller Mustang MC.
Let's look at the 1994-95 Mustang SVT Cobra master cylinder with a standard bore of 23.8 mm.

A 23.8 mm piston has an area of 444.9 mm.
This would provide a 13.9% increase of area for the FRONT calipers compared to the stock 240 MC.
 It would provide a 28% increase of area for the REAR calipers compared to the 240 MC.
A small change in piston bore size can make a significant difference in how the pedal feels.
So one can argue that even a 23.8 mm MC might be proportionally be a bit too big for a front/rear R brake conversion, although I suspect it will be hard to notice.


  I have seen some comments that the 2004-07 S60R/V70R had a larger master cylinder than a 240.  Well yes, it had a 25 mm bore. I don't know how useful this comparison is. The master cylinder for the R is Volvo PN 8602365. It has a standard bore (not a stepped bore) of 25 mm. 

OTHER FACTORS TO CONSIDER
 
ONE MORE FACTOR you should think about is how efficient your VACUUM BOOSTER is.  If you have an engine which offers lots of vacuum to your brake booster, then that booster will be stronger and will offer MORE POWER ASSIST. If you have a lower vacuum engine, such as a B21FT (7.5 to 1 static compression ratio) or if you have a bigger than stock camshaft, which reduces the vacuum to your booster, then you'll have potentially LESS POWER ASSIST. 

And a factor which I have not yet mentioned here. This is the increased braking leverage that a bigger brake rotor provides. I don't know how much difference this makes in choosing a master cylinder, but it will be a factor of some sort in your decisions.

Here's a thread with a number of comments from people using Mustang master cylinders.

http://forums.turbobricks.com/showthread.php?t=349379

  BOTTOM LINE: You might need to experiment with more than one master cylinder. I have compiled a number of different MCs with full piston specs HERE.

Again, your comments are welcome.



WILWOOD PROPORTIONING VALVE
 Aris from Greece took a big step when installing bigger brakes and eliminated the original brake junction block in his 240. Instead he installed a Wilwood Adjustable Proportioning Valve, PN 260-11179.
His R caliper front and rear installation is detailed HERE.

Since this Wilwood valve uses 3/8-24 Inverted Flare ports (Inverted Flare is the same as a Double Flare) and the original Volvo brake lines had fittings threaded as 10 x 1.0 mm Bubble Flare, Aris cut the lines and re-flared them to a double flare using new 3/8-24 brake line nuts for all of the lines going to this valve. The Volvo brake pipes
are the correct size for the change in fitting size, so there is no need to change to a different size pipe. Just new fittings are needed if you can DIY flare the lines.. 

Here's an image below showing the BRAKE LINE ROUTING to the proportioning valve.
Using the smaller front bore from the MC for the rear calipers was a good choice. The rear calipers need less fluid volume than the fronts.
Since a pre-ABS 240 has two lines going from the junction block to the rear calipers (going through factory pressure reduction valves), Aris removed the reduction valves and changed to one line going rearward to a simple junction near the rear end, which then splits to both rear calipers.

Here's a video below about the Wilwood Proportioning Valve.

https://www.youtube.com/watch?v=1oahuttkEws





240 WILWOOD BRAKES

Learning brake voodoo can be overwhelming. I came across this brake pressure chart from Wilwood that may offer just a small bit more understanding of pedal effort and its relationship to master cylinder bore size.

A PDF of this chart can be found at: https://www.wilwood.com/PDF/Flyers/fl162.pdf



Wilwood Front Caliper Adapter Kit
by Avalanche Performance

The adapter kit featured here is no longer available.
  In 2010 Avalanche Performance Technologies came out with a 240 adapter kit for installing Wilwood brake calipers and Wilwood rotors on the front of a Volvo 240. 
This chapter will show the installation on my 1984 242 Turbo.


This brake kit was designed to offer an inexpensive solution for 240 owners who wanted larger front brakes. While less expensive than the R-brake conversion, it also allowed for more wheel options, since this brake package used smaller 12.2 inch rotors and would fit inside smaller wheels compared to the R-brakes with big 13 inch rotors. 

 
Referring to the photo ABOVE, the Avalanche kit came with two custom aluminum adapters with mounting bolts, two custom aluminum rotor hats, and the brake line pieces shown, which go from the caliper to the flexible line junction at the 240 strut tube. Also included were two M10-1.0 plugs for the brake line junction block.  The customer then purchased rotors and calipers from Wilwood.
 
    
 
Here are the Wilwood calipers (left and right respectively) bolted up to the adapters. 

These Wilwood calipers are LUG MOUNTED



I used the following Wilwood items:

 
  CALIPERS: WILWOOD Billet Forged Superlite (FSL),
PN WW120-7431L and WW120-7431R
(NOTE: These caliper parts numbers above are no longer available.
Wilwood discontinued this caliper with an EXTERNAL crossover. The new model now has INTERNAL crossovers: Wilwood Forged Superlite (FSL) Internal, available with 1.25 inch bore, 1.38 inch bore, 1.62 inch bore, or 1.75 inch bore or may be ordered with staggered piston sizes.
These new "Internal" calipers have internal fluid crossovers instead of external crossover tubes as seen in the old FSL caliper photos here.

WILWOOD Billet Forged Superlite (FSL) Specs.
 
Four pistons, 1.38 inch (35 mm) bore.
Made for 1.25 inch (32 mm) thick rotor. 
For more detailed info on this caliper, click here to search the Wilwood page or click here for the Wilwood FSL pdf.
The brake line port on this caliper is threaded 1/8" x 27 NPT (female).



ROTORS:
This kit was made for any Wilwood 12.19 x 1.25 inch (309 x 32 mm) rotor with 8 bolts, 7 inch bolt circle. 
I opted for Wilwood Ultralite 32 fin curved vane rotors, PN 1602895 (left)
and PN 1602894 (right).
This photo below compares the Wilwood rotor to the front R rotor.


These hard brake lines were constructed as follows:
90 degree fitting, 1/8 inch x 27 NPT male at the caliper to female on other end (Wilwood calipers use 1/8 NPT brake ports).
Adapter: Straight 1/8 inch x 27 NPT male to
3/8 inch x 24 double flare female brake fitting.
3/16 inch brake line (4.75 mm).

3/8 x 24 brake nut with double flare.
Other end to Flex hose: Standard Volvo 10 x 1.0 mm bubble flare male (Europe).
Flex hose (one per side), stainless braided, 10 x 1.0 mm bubble flare (Europe) female on both ends.



BRAKE LINE
NOTE: You may use 3/16 inch brake lines for all Volvo 240 applications.  Metric brake lines in this size are 4.75 mm. 3/16 inch equals 4.76 mm.
FITTING NOTE regarding 10 x 1.0 mm Bubble Flares: Make sure you get fittings that are designated as 10 x 1.0 mm EUROPEAN Bubble Flare. There are JAPANESE 10 x 1.0 Bubble Flare fittings out there, which will not fit.
A good source for correct Volvo threaded fittings: Belmetric www.belmetric.com/bubble-flare.

NOTE ABOUT BRAKE LINE ADAPTERS: Constructing brake lines using multiple adapters is not the best solution if it can be avoided. Keeping adapters to a minimum will reduce the chances for leaks. 
In a perfect world, this caliper would have come with standard Volvo 10 x 1.0 mm bubble flare ports. They don't. Whenever possible, do some careful research with an effort to keep adapters to a minimum. This adapter setup uses what was originally recommended by Wilwood, however fewer adapters would have been better.

If you search, you will find that there are more proper adapters which will adapt a 1/8 x 27 NPT port DIRECTLY to 10 x 1.0 mm (European) bubble flare.
For example, here are some made for VW by Empi:
Empi 18-1107 90 Deg Male 1/8" NPT to Female 10mm X 1.0 Bubble Flare https://www.amazon.com/dp/B07979K5TH.
Empi 18-1102 Straight Male 1/8" NPT to Female 10mm X 1.0 Bubble Flare https://www.amazon.com/dp/B0748NNSZR.
Using one of these adapters at the caliper would eliminate the need for the middle adapter in the above photos.


BRAKE PADS for Wilwood 7420
This Wilwood caliper uses Wilwood pad type 7420.

I read up on the pad compounds in Wilwood's site and I chose the BP-10 Smart Pad (formerly called PolyMatrix D). This pad seemed to be a good choice for high-performance mostly street use.

I used these for years. They performed great, but for some reason they tended to squeal very loudly when very, very hot.

More choices recommended by other Volvo owners for mostly street use:
Wilwood Poly Matrix Q for 7420 caliper. I have not tried these.
Porterfield R4S pads for 7420 caliper.
I put these on my car in 2023 and I've been happy with them.


  The rotor to hat fasteners were not supplied with the adapter kit, so I ordered Wilwood socket head bolts, 5/16" x 24, PN 230-0150 (8 pieces with washers, 2 sets needed).

    
I cannot over-emphasize the importance of test fitting parts like these before committing yourself to the full installation. 
The first thing I found (I expected this would happen) was that the brake backing plate interfered with the new adapter and caliper.  The main interference was found near the bottom of the adapter bracket.  Trimming the backing plate is a solution, but I chose to remove it instead.  The hub needs to be removed to get the backing plate off.  The second photo below show the backing plate removed.  This will be a good opportunity to re-grease the bearings.  Also, the rubber seal on the inside end of the spindle would be a good thing to replace, since they are cheap and still available. 
 


Here I'm test-fitting the caliper bracket after the backing plate was removed.   

Here's something to be cautious of. If you're using caliper mounting bolts that have an un-threaded shoulder (like the original Volvo bolt in this photo), check to make sure the bolt threads all the way in.  I've seen more than one type on cars from the factory. The kit came with a washer to use here between the bolt and adapter (it's important to use a washer when bolting to aluminum), but since the adapter bracket is a little thinner than the original 240 caliper mounting arm, the original bolt would not seat completely.  Simple fix: One additional washer was added. 
   


Here is a snag that stopped my installation. 

I knew ahead of time that there could be interference between the deep spokes on the Eiker (Polaris replica) wheel and the Wilwood caliper.
There WAS interference.
 

 
In this photo ABOVE, I did another fit test by placing an 8 mm spacer behind the wheel to move the wheel away from the caliper 8 mm. This allowed a comfortable clearance distance of about 1.5 to 2 mm between the wheel spoke and caliper. So these wheels would not fit on a 240 with this kit, unless the wheels were spaced outward about 8 mm. 
A 240 wheel stud normally protrudes about 25 mm out and the LUG NUT will usually engage about 15 mm of thread on the stud.
Using an 8 mm spacer would have reduced that engagement too much.  Longer wheel studs would have been a solution, but I put off installation for a while.
MORE BELOW.


 

I then bought different wheels, which had a bit more room behind the spokes.
These wheels are also 17 x 7.5 inches. They just fit better.
I have more details about these wheels at https://www.240turbo.com/ 





More Big Brake Conversions
Wilwood Caliper Adapter and Rotor Hat Kit by Kevin Hawkinson.  A VERY SIMILAR kit to the above Wilwood kit.
This kit shown was being offered at one time in the below Turbobricks thread.





BREMBO Four Piston 240 Front Caliper Adapter Kit
from BNE Dynamics (Kaplhenke Racing).
This is a kit which Includes new calipers and adapters for your choice of rotor diameter options: 11.25 inch (286 x 26 mm) / 11.88 inch (302 x 26 mm) / 12.44 inch (316 x 28 mm).  This allows you to find a larger brake kit which will fit under a number of differently sized Volvo wheels.  
This 4-piston caliper keeps the same stock 240 sized 38 mm piston diameters, so that there is no need to upgrade your master cylinder.
https://www.bneshop.com/collections/240/products/240-medium-brake-kit-brembo-calipers
https://www.bneshop.com/collections/240-medium-brake-brembo-kit

These Brembo calipers are LUG MOUNTED


More info in the TB Discussion Thread: https://forums.tbforums.com/showthread.php?p=6162206



RX7 BRAKE CONVERSION
The brake conversion below was originally introduced by DVS Performance Parts in Australia at http://www.dvs.net.au.
The conversion uses an adapter bracket and a front caliper from an 86-91 Mazda RX7 Turbo II, GXL, GTU or convertible (using 5 stud wheels).
LARGER ROTORS:
11.25" diameter (286 x 22 mm) rotor from a Volvo 7/9 series. This adds almost one inch of diameter over a stock front 240 rotor. Supposedly this adaptation will fit inside most 15 inch wheels, although a small (~5 mm) spacer may be needed for a 240 Turbo (15 inch Virgo) wheel. 
Additional discussion about this can be found at
https://forums.turbobricks.com/showthread.php?t=68630
An RX7 kit may be found in the USA at https://yoshifab.com/store/rx7-brake-adapter-bracket-kit.html
   

In January 2013 I received an interesting email from Willy Reerink in the Netherlands.
Hello Dave,
I am working on the ultimate Volvo 240 to Mazda RX7 brake upgrade. My story is as follows:
In 2011 I bought a Ford Taunus dragrace car in Sweden and bringing it to the Netherlands where I live. As the car was built in Sweden they used Volvo 240 spindles and calipers. But when the car was built years ago it was much slower then with its current engine. I bought it with a 1.000 HP Chevy Small Block engine in it. It never raced with this engine and brakes. Last year we made the first runs, and brakes seemed not to do anything at all. So I first overhauled the brakes, and used ECB race pads. Brakes work now but the car is reaching 250 kph (156 MPH) and that makes braking even more exciting then accelerating!
 
Anyway, I looked for a brake upgrade and decided that to me the best solution was the RX7 upgrade. Cheap, easy to mount, and much lighter then the 240 ones.
 
I am still working on it because I do encounter some problems and I am not a mechanic. I do this for the first time.
 
But I can make a good comparison. The Volvo 240 ones did have just enough capacity to stop the Taunus, but nothing left (I prefer braking with the chute now). So lets see what happens this summer when the RX7 brakes are installed and how they manage high speeds. We will see.
 
You can follow my brake upgrade on my blog at:  http://turbotaunus.wordpress.com/brake-upgrade/

Porsche Cayenne 17Z 6-Piston
Added 2021
The below Porsche Caye
nne 17Z front and rear big brake conversion kit for 240 is now available at BNE Dynamics (Kaplhenke Racing).

https://www.bneshop.com/collections/240/products/240-brembo-17z-adapters




Porsche Cayenne Calipers on a 240

July 2013, by J. Homer.
Here's a great looking adaptation of Porsche Cayenne brake calipers on a 1990 240 Owned by J. Homer.

Original Cayenne brake thread: https://forums.turbobricks.com/showthread.php?t=281934
  J. Homer's 240 build thread: https://forums.turbobricks.com/showthread.php?t=219119

Front calipers: 17Z left and right 6-piston calipers from a circa 2004-10 Porsche Cayenne / VW Touareg / Audi Q7 Models using large 330 x 32 mm front rotors.
This caliper has a staggered piston design. Pistons are 34 mm, 36 mm and 38 mm (6238 mm piston area per caliper).
NOTE: This caliper has 37.5% more piston area than a 240 factory front caliper.

Rear calipers: 17Z left and right 4-piston calipers from same vehicle using 330 x 28 mm rear rotors.
This caliper has a staggered piston design. Pistons are 28 mm and 30 mm (2645 mm
piston area per caliper).
NOTE: This caliper has 16.1% more piston area than a 240 factory rear caliper.


Rotors used: Standard Volvo S60R (Brembo), 13 inch (330 x 32 mm) front and 13 inch (330 x 28 mm) rear.
Pads: OEM style Pagid pads for Porsche were used in this project.


These Porsche calipers are LUG MOUNTED


REAR CALIPER and adapter.
Because of the staggered piston sizes on these calipers (similar to the Volvo R calipers) and the fact that on the Cayenne they were originally mounted on the front of the rotors (and these are going behind them on the Volvo), Jacob flipped the crossover pipes and bleeder screws to swap them.
Having the staggered pistons in the proper order will be best for eliminating potential uneven pad wear.


FRONT CALIPER and adapter.

 
Front caliper in place.


This is the drum portion of a stock 240 rear rotor.

The disc part has been cut away.  This drum is then placed on the hub, then the S60R rear rotor is placed on. This will retain the stock 240 parking brakes. 


Rear rotor in place over parking brake drum.

This large 27 mm bore MASTER CYLINDER is from a 1994-95 Mustang GT. 
The Porsche calipers need more fluid volume to move the brakes than stock calipers do.  The installer felt that a smaller master cylinder would not be adequate and would probably create a longer pedal travel. He has commented that the larger master cylinder has kept the brakes from becoming too grabby and they're easier to modulate. 


The master cylinder used for this conversion was identified as:
 
1994-95 MUSTANG GT MASTER CYLINDER
 
Ford PN 130.61062, Centric PN 13061062, Raybestos PN MC390185, Dorman PN M390185.
Bore size: 1.0625" (27 mm). Standard bore, same front and rear.
Push rod depth: 1.4 inches (35.5 inches).
 

 
Rear brake line port is M10 x 1.0 mm bubble flare, so the Volvo brake line fits that.
Front port is M12 x 1.0 mm bubble flare so an adapter or new flare is needed.
  Brake Line Thread Adapter, Male M12 x 1 Bubble to Female M10 x 1 Bubble: Here's one:
https://www.ebay.com/itm/Brake-Line-Thread-Adapter-Male-M12-x-1-Bubble-Female-M10-x-1-Bubble-/331605500736

More variations of this Mustang master cylinder can be seen HERE.


Also if you don't care for the strange looking reservoir, a stock Volvo reservoir can be fitted to this MC with a bit of effort. Reportedly, some extra care must be taken to ensure a tight seal. 
This link discusses that:
https://forums.turbobricks.com/showthread.php?t=349379
A plug pigtail is available to fit the Ford low fluid sensor: Dorman 645-920


To correctly fit the Ford master cylinder properly, the push rod on the original vacuum booster
needed to be extended approximately 0.8 inch (20 mm) so the rod just touches the MC piston end when the brake pedal is at rest.
The stock position (LEFT) and the extended position (RIGHT) is shown below.

 

MORE INFO:
J. Homer's Cayenne brake thread: https://forums.turbobricks.com/showthread.php?t=281934
J. Homer's 240 build thread: https://forums.turbobricks.com/showthread.php?t=219119
Adapter kits:  https://www.bneshop.com/collections/240/products/240-brembo-17z-adapters



Cadillac ATS Brembo front calipers on a 240

By Edison Bender, November 2014
This adaptation uses Cadillac ATS front 4-piston calipers and 13 inch rotors from an S60R/V70R.  It will fit with most 17 inch wheels. An advantage of this caliper is that they are only about $120 each new.  The calipers may be purchased from various OEM suppliers and even Rock Auto  has them under the AC Delco brand.  They use the same brake pads as the S60R/V70R, STI or Evo, which uses 4-piston Brembos. 

The adapter brackets have been custom made and are available in the below link.
Turbobricks thead and purchase info:
https://forums.turbobricks.com/showthread.php?t=305147


These calipers are LUG MOUNTED






Dick Prince 240 Race Car Brakes
This information was compiled many years ago, but it's certainly still very useful. Dick Prince in Australia included a lot of useful data, which went into the making of his racing 240 dual master cylinder (non-boosted) brake system.
Certainly some of this info will be of limited use for a street car, but that's OK.
Click here for his page: http://www.ovlov.net/page.php?page_name=brakes

Volvo 740 front hubs to receive rotor hats.
 
DBA069 Mustang rotors 330mm x 28mm (left and right hand).
 
AP Racing 6-piston calipers CP5570 (Pistons: 27.0 mm x 2, 31.8 mm x 2, 38.1 mm x 2).

17mm thick competition disc pads.
Machined alloy caliper mounting adapters from Brunton Engineering.
Two 5/8 inch (15.875 mm) bore Girling master cylinders with reservoirs.
Master cylinder balance bar and adjuster cable.
Removal of factory split circuit brake lines and factory reduction valves.
Modifications to Volvo pedal box (brake pedal ratio changed from 4:1 to 4.5:1).
Clutch master cylinder with integral fluid reservoir.
 

Volvo brake upgrade calculations:
Car plus driver = 1250kg (2755 lbs).
Static weight distribution: 55% front = 690kg, 45% rear = 560kg.
Braking at 0.9g with vehicle centre of gravity 0.5m above road, produces a rotational moment about the tyre contact patch of 0.9 x 1250 x 0.5 = 560kg.m.
For Volvo wheelbase of 2.77m this creates a weight transfer of 560/2.77 = 205kg, that is +205kg at front axle, -205kg at rear axle.
Front axle load under 0.9g stop = 690 (static) + 205 = 895kg or 447.5kg/wheel.
Rear axle load under 0.9g stop = 560 (static) - 205 = 355kg or 177.5kg/wheel.
Tyre radius (Yokohama A032R, 245x45/17) = 0.32m (approx. 12.8").
Front brake torque required = wheel load x 0.9g x tyre radius, = 447.5 x 0.9 x 0.32 = 129kg.m (approx. 930 ft.lb).
Competition disc pad coefficient of friction = 0.45 approx.
Rotor O/D = 330mm Approx. radius to centre of pad = 0.155m, therefore Clamping force to generate brake torque = 129/(0.155 x 0.45) = 1,850kg (=4,070lb).
Front calipers: CP5570 6-piston: total piston area 50.1cm2.
Area of 3 pistons 27.0 mm,  31.8 mm, 38.1 mm (per side) = 25.05cm2 = 3.883 sq.inch.
Therefore hydraulic pressure = 1,850/25.05 = 73.85 kg/cm2 (1,048psi).
Master cylinder 5/8" ID (15.875 mm), area: 1.98 cm2, so rod force for 73.85kg/cm2 = 73.85 x 1.98 = 145kg.

For rear, similar calculations to those above:

Rear brake torque required: 177.5kg wheel load x 0.9g x 0.32m tyre dia.= 51kg.m.
Clamping force req'd = 51/(mean disc radius 0.125m x coeff.of friction 0.45) = 905kg (1,991 lb).
Rear calipers: standard ATE 2-piston each 1.49" dia. = 11.25 cm2 per side.
Hydraulic pressure req'd = 905/11.25 = 80.4 kg/cm2 (1,140psi).
Master cylinder 5/8" dia. area = 1.98 cm2.
Rod force for 80.4kg/cm2 = 80.4 x 1.98 = 159kg (350 lb).
Brake pedal: Volvo standard pedal ratio = 4:1.
For this car, modified to approx. 4.5:1
Total rod load on twin master cylinders = 146kg (F) plus 159kg (R) = 305kg.
So for new pedal ratio of 4.5:1 the foot pedal force for 0.9g stop is = 305/4.5 = 68kg or 150lb.

Note that rod force for the two master cylinders are similar (146kg, 159kg) which means that the bias balance bar will be near centered.
Depending on your F/R caliper areas, you may need to select a different master cylinder diameter to achieve approximately equal rod forces.


I have found that in the Volvo racecar, a pedal force of 150lb is quite OK and in keeping for this application.

For a lighter road application, a pedal force of 100lb (45kg) will be more suitable. This can be achieved with an aftermarket pedal box, like Tilton with a pedal ratio of 6.2:1


SPECIAL NOTE: The calculations above are provided for the interest of motorsport enthusiasts only. Not for road use.

Dick Prince also prepared an "owner's manual" for this car with more detail:
Link to PDF: https://1drv.ms/b/s!AtjXfjFx5NHNjakt9r9kaL2_GeVI9Q









Renault Megane front calipers on a 240
Info from Morten F. of Denmark October 2022
This adaptation uses 4-piston calipers from a Renault Megane III RS.

Rotors are 336mm XC90 Discs. Front wheel adapters are only spacers to push the wheels further out +5 offset.
 Brake lines are plugged off in the same manner as shown in Alternate 1 HERE. Works great, though the balance needs some work. Front brakes grab a bit harder than rears.
Brake lines are homemade with AN Stainless fittings and PTFE Hoses.

ADAPTERS:
These calipers are radial mounted and the adapters needed to convert them to a lug-mounted type to fit the 240 spindle. Morten designed and 3D printed adapter prototypes first, until he was satisfied a good fit was achieved. The
adapters were designed in Inventor and then CNC milled from an S355 steel block. Morten did not trust aluminum enough, though the weight saving would be significant. The caliper to adapter bolts are M14x1.5 fine threaded grade 10.9 bolts. Adapter to strut bolts also grade 10.9 bolts. 

     





XC90 front calipers, rotors on a 240

These adapters are made by Andersson Steel & Speed in Sweden. They allow the use of XC90 336 mm rotors and calipers on your 240 front. These typically requires at least a 17 inch rim.
https://www.anderssonsteelspeed.se/en/




Misc. Master Cylinder Info
I have begun compiling some useful alternate master cylinder info. 
These are alternate master cylinders that some might consider using or comparing to when looking for for alternate piston bore sizes in a master cylnder that might fit a 240.
These can be compared to a 240 MC with the following specs:
       Non-ABS 240 tandem master cylinder has a STEPPED bore: 22.3 mm (0.878 inch) primary (REAR) bore, 15.75 mm (0.62 inch) secondary (FRONT) bore.
(Average bore size: 19 mm).
    ABS 240 tandem master cylinder has a STEPPED bore: 22.3 mm primary (REAR) bore, 19 mm secondary (FRONT) bore.
(Average bore size: 20.65 mm).
M10 x 1.0 bubble flare (European) brake line ports.
 

  
240 Master Cylinder Part Numbers:
     240 non-ABS Brake line ports on left PN 8111005-8.
   240 non-ABS Brake line ports on right PN 8111006-6.
240 with ABS PN 3530972, 8251131, 8602015.



Volvo 740 1986-88, 760 1986, 780 1987, 940 1991.
Volvo PN 1273243, 1359693, Dorman PN M39641.
STEPPED BORE:
22.2 mm primary (REAR) bore, 15.875 mm secondary (FRONT) bore.
M10 x 1.0 bubble flare (European) brake line ports ON LEFT/FRONT or on BOTTOM.




Volvo 940 1992-95, 960 1992-97, S90-V90 1998.
Volvo PN 3530352, 6819771, Dorman PN M390090.
STEPPED BORE:
23.8 mm primary (REAR) bore, 20.65 mm secondary (FRONT) bore.
M10 x 1.0 bubble flare (European) brake line ports ON LEFT or on BOTTOM.




Dodge Dakota 1987-93.
Dodge Chrysler 4294311, 4294312, 4294721, 4897208AA, Dorman PN M39638.
  STANDARD BORE:
24 mm.
Rear port: 1/2-20 thread. Front port: 9/16-20 thread. Outlets on LEFT.





Dodge Plymouth Colt 1987-89, Hyundai Excel 1987-89, Mitsubishi Mirage 1987-88, Mitsibishi Precis 1987-89.
  Hyundai PN 58510-21301, 58510-21302, 58501-21303, Mitsubishi PN MB238691, MB238700, MB316242, Dorman PN M39639.
  STANDARD BORE:
0.813 inch (20.65 mm).
M10 x 1.0 double flare (Asian) brake line ports ON LEFT.




Dodge Plymouth Colt 1989-92, Eagle Summit 1990-92, Mitsubishi Mirage 1989-92.
  Mitsubishi PN MB534019, Dorman PN M39722.
  STANDARD BORE:
0.813 inch (20.65 mm).
M10 x 1.0 double flare (Asian) brake line ports ON LEFT and REAR TOP.




Ford Mustang SVT Cobra 1993
Ford PN F3ZZ-2140-A, Raybestos PN MC390125, Dorman PN M390125
STANDARD BORE: 1 inch (25.4 mm).
REAR brake line port: M10 x 1.0 mm bubble flare.  FRONT port: M12 x 1.0 mm bubble flare.

Ford Mustang SVT Cobra 1994-95

Ford PN F4ZZ 2140-B, Raybestos PN MC390217, Dorman PN M390217
STANDARD BORE: 15/16 inch (23.8 mm).
REAR brake line port: M10 x 1.0 mm bubble flare.  FRONT port: M12 x 1.0 mm bubble flare.

Ford Mustang GT 1994-96
 
Ford PN 130.61062, Centric PN 13061062, Raybestos PN MC390185, Dorman PN M390185.
STANDARD BORE: 1.0625 inch (27 mm).
REAR brake line port: M10 x 1.0 mm bubble flare.  FRONT port: M12 x 1.0 mm bubble flare.


 
Ford Fiesta 1988-93
FORD PN E8BZ-2140-A, Dorman PN M39720.
STANDARD BORE: 0.750 inch (19 mm).
M10 x 1.0 brake line ports on RIGHT.




Ford Ranger 1987-89

FORD PN E7TZ-2140-D, Dorman PN M39633.
STANDARD BORE: 0.938 inch (23.83 mm).
REAR brake line port: M18-1.5.  FRONT port: 9/16-18. Ports on RIGHT.




Mercury Tracer 1988-89
FORD PN E8GY-2140-B, Dorman PN M39742.
STANDARD BORE: 0.875 inch (22.22 mm).
REAR brake line port: M10-1.0.  FRONT port: M10-1.0. Ports on RIGHT.




Nissan Pulsar NX 1985-86, Nissan Sentra 1984-85, Nissan Tsuru 1982-85
Nissan PN 46010-04B05, 46010-04B06, Dorman PN M39555.
  STANDARD BORE: 0.750 inch (19 mm).
M10 x 1.0 double flare (Asian) brake line ports ON LEFT and REAR TOP.




Nissan 280ZX 1982-83
Nissan PN 46010-P9100, Dorman PN M39408.
 
STANDARD BORE: 15/16 inch (23.8 mm).
M10 x 1.0 double flare (Asian) brake line ports BOTTOM.




Saturn 2000-2002
GM Saturn PN 21013195, Dorman PN M630056.
STANDARD BORE: 0.875 inch (22.22 mm).
REAR brake line port: M12-1.0.  FRONT port: M11-1.5. Ports on RIGHT.






Miscellaneous Stuff:
OTHER INTERESTING BRAKE PHOTOS

These are interesting.  Pretty simple design.
I found these pics on a Porche 944 site. 
Anyone want to make some sets for 240's??


The below photos are Porsche calipers adapted by a European 240 owner for an '81 244 Turbo.   These calipers are considered radial mount.  Custom two-piece rotors were used, however the rotor size is not known.  Nice, simple adaptation.   These pics were located in the following Turbobricks thread:  https://forums.turbobricks.com/showthread.php?t=22070


These calipers are RADIAL MOUNTED




Vacuum Pump
to Improve LOW Brake Booster Vacuum
Hella Vacuum Pump
Volvo Vacuum Switch
Pump/Vac Wiring Diagrams
Volvo Part Numbers
Rubber Isolators
Installation and Issues
In 2024 I began studying this after seeing it discussed in some TB forum posts.
Volvo used this idea to improve brake booster response in FWD cars. I'm using Volvo parts and info below, which should help if you want to use this on your older car too.
These components below were originally installed by Volvo in their early 2000s and later FWD cars. Many BMWs and Mercedes in the same era got these too. Apparently those engines needed some supplemental manifold vacuum to keep the brake systems happy. I think a big part of this for VOLVO was related to the Dynamic Stability Traction Control (DSTC), which used the ABS brake system to enhance handing in extreme handling situations. Since the DSTC needed brakes to fully function, even when at full throttle or under turbo boost, it needed a way to provide full vacuum to the brake booster independent of engine vacuum. So Volvo installed a Hella vacuum pump to keep the booster fully charged with vacuum at all times.  These were probably phased out when some manufacturers began using electric brake systems and vacuum boosters became a thing of the past.

My low compression B21FT doesn't make much vacuum on it's own.  For a while I used a high-performance Unitek cam, which made even less vacuum.  At times vacuum was BELOW an acceptable level that the brake booster needed, so brake assist might work ok or it might not.  I changed to a milder cam and the brakes were all better, but then I missed the bigger cam.
   

Useful Volvo Part Numbers
31317530 (30793053) Vacuum Pump UP 28 (believed designated for 2004-12 S40, V50).
31400692 3-way vacuum switch, Volvo (same one I bought).
926-887 (Dorman)
Alternate Dorman Vacuum Switch PN 926-887. Identical to Volvo switch (same one I also bought).
30665071
Retainer-clip for vacuum switch.
31400693
Another 3-way vacuum switch. Same function. Hose nipples are pointed differently.
8683264
Bracket for vacuum pump. Same as the bracket I used (for 2004-12 S40, V50).
30648920 (8633631)
Bracket for vacuum pump. Different mounting style (for 2004-09 S60).
30636534
Rubber isolator for pump mount. Same larger isolator pictured below. One for each side (for 2004-12 S40, V50).
30636535
Rubber isolator for pump mount. Same smaller isolators pictured below. Two for each side (for 2004-12 S40, V50).
30648921
Special M6 shoulder bolt with flange. Two needed. Same as shown below.
985866
M6 lock nut with flange. Two needed. Same as shown below.
30620537
Rubber isolator for pump mount (this is a different style isolator I didn't try).



While this is not the only style of vacuum pump Volvo used, this seems to be the most common.
THIS is the Hella UP 28.
 
So I decided to try out a UP 28. Other Hella pumps that you might read about are UP 30 and UP 5.0, which are larger.
Volvo assigned a lot of different part numbers for the Hella UP 28, since this pump was used for a number of Volvo models over a number of years. A new pump can be expensive, especially if you buy one from Volvo ($300 and up). If you're shopping for a new "genuine" Hella pump from an unproven source, use caution.  There are definitely some Chinese low-cost knock-offs, so there may be some counterfeits being sold as genuine Hella. If you see a really low price for a new "geniune Hella," I would be careful. I saw one on Amazon which said it was a Hella, but the price was really low. The reviews gave it away.  A number of people complained how their new pump failed in a month. Nope!  I decided to try a used one below from eBay. It came with a bracket and rubber isolators, which I'll show in detail further below.

The Hella UP 28 is rated to pull about 14.7 Hg (inches/Mercury) of vacuum within about 4 seconds or (if needed) up to about 20 Hg of vacuum within 11 seconds at 13 volts. It sucks from that front nipple and exhausts from an exhaust port on the back side. It uses 15 amps max, or about 10 amps average between thresholds.
Sources: https://myhellalights.com/up28https://www.hella.com/10069076a_AM0.pdf
If you're curious how one one these sounds when on, here's a short video: https://www.youtube.com/watch?v=qzGbMzJ7bPk&t=85s
 
.

VACUUM SWITCHES
 A vacuum switch or sensor is needed to trigger the pump on or off so it doesn't just run all the time.

I've seen a few videos where it appears people wired these in cars (not Volvos) to run full time. This pump is NOT quiet. And running it all the time will probably just wear it out fast. It's only rated to run about 1000 to 2000 hours total. Using a vacuum switch to make it run only when the booster needs a burst of vacuum makes a lot better sense.

This image below shows one of the ways Volvo would plumb vacuum hoses between the brake booster, intake manifold and vacuum pump. This method uses three separate parts, which all include one way check valves to allow vacuum to flow only where it's needed, but keeping out boost. I am not planning to use these particular devices. My plan was to use a different style switch Volvo used.


The vacuum switch I chose is BELOW. It's an all-in-one switch with all of the check valves built in.
The function is sort of the same as the arrangement above.
The switch needs to sense the vacuum in the brake booster, which this switch below does. If vacuum is below a specific level, it'll trigger the pump to "recharge" the booster, so in theory it should be ready when you push the pedal.
  While a genuine Volvo switch is available, the FIRST switch I bought was a less expensive replacement version made by Dorman, PN 926-887. Cost was $36.

INITIAL PLUMBING ARRANGEMENT
 

A PN for a genuine Volvo switch is 31400692 (I think Hella also made these too). The genuine Volvo switch is also available from FCP: www.fcpeuro.com/31265825.  I bought one of these later, after first buying a Dorman aftermarket one. More about that in the Installation Section.
 The hose "ARRANGEMENT 1" above was drawn up based on my interpretation of Volvo diagrams, one shown above RIGHT, and reinforced by these videos which show the same: youtube.com/Ifx5z8hQqEI, youtube.com/PRbWD2OGytk.  So it's pretty clear to me I had the "proper" arrangement of this switch, HOWEVER, now I DO NOT recommend this arrangement. Keep reading and you'll see why I changed it to "Arrangement 2" in the Installation Section.

 
This 3-way switch is designed to be placed in the hose between the manifold vacuum port and brake booster. This way your booster is still directly connected to manifold vacuum and if you're vacuum pump ever fails, vacuum can still be available from the manifold.
This switch has several one-way check valves. One check valve is at the manifold vacuum barb, so turbo boost cannot enter it from the manifold. The barbed nipples are made for 3/8 inch ID hose. A fairly stiff hose that will not collapse under vacuum is needed.


A "proper" connector for this switch is a special one made for a connection that will fit these TWO RAISED Ridges above.
If you don't have that special plug, a common 2-pole EV1 fuel injector plug can be used, but first you need to TRIM OFF the two raised ridges as shown below.

VACUUM SWITCH ON-OFF BENCH TESTING:
I did some vacuum switch testing with a Mityvac vacuum hand pump. This switch is normally closed (or ON) at ambient pressure. So if you wire it like the below RELAY diagram, it should come on as soon as you turn the key to 'RUN'. The switch then OPENS (shuts off) at
about 14 Hg (inches/Mercury) vacuum. Then as vacuum drops, it comes back on at about 13.25 Hg.
I tested BOTH a NEW DORMAN switch and a NEW genuine VOLVO switch. The results were identical.
It must be noted that this switch appears to have a very, very small LAG threshold where its turn-ON setting is slightly lower than its turn-OFF setting, but only about 0.75 Hg apart. This ON-OFF setting cannot be adjusted and having them so close together may create a problem. Definitely you need to make extra certain there are no leaks anywhere after installation. I have a VIDEO below in the INSTALLATION Section showing the initial problem I had with "Arrangement 1" plumbing.

.
WIRING DIAGRAMS

This first wiring diagram below comes from Volvo diagrams (TP3976202, 2005 60 series, page 102), which shows the vacuum pump and switch I'm using. According to this diagram, Volvo wired DIRECT POWER through the vacuum switch to the pump (with NO RELAY). This is puzzling to me, since the vacuum switch does not appear to me it would be reliable for a long time of repeated 15 amp on-off loads.

If you think using a relay is a better idea (like I do), you'll probably agree with this diagram BELOW, which is how wired it.
Polarity is not important for the vacuum switch connection. The switch can be wired to trigger the ground to activate a relay. Then the relay can handle the heavy load and activate the pump.

If the Hella pump you have came with an electrical plug, it will probably be the exact same as the above Yazaki female. If you need terminals for these connectors, they're Yazaki 2.8 type.  I didn't have a mating Yazaki plug, so I changed it to an AMP ATP connector BELOW (rated at 25 amps).  More info about AMP ATP connectors is detailed at https://www.240turbo.com/crimps.html#deutsch.


Some more useful documents.
 

.
.
Rubber Isolator Detail




INSTALLATION BEGINS HERE

I decided I didn't need the extra mounting arms on this bracket, so I trimmed off some metal.



The best place I found to mount this with decent room seemed to be a flat spot on the left inner fender, below the brake booster and master cylinder, just above the frame. It's awkward getting in there and I needed to use a 90-degree drill. I installed thread inserts and you can see those poking out on the back side, just behind the front left strut.


I wanted the fuse and relay to be easily accessible, so I used a rubber-lined harness mount to attach them to my diagonal strut brace.


INITIAL TESTING FAILURE
As mentioned, this pump was installed first using the Dorman vacuum switch and using "Arrangement 1" hose routing. This video below was a static test with the key ON and engine NOT running.  It was clearly not working as I had hoped.
https://www.youtube.com/watch?v=3mortR_pzr8

I think that CLICK-CLICK CLICK ON-OFF issues may be due to vacuum switch OFF and ON setting being so tightly close together that the switch might be having trouble shutting off and staying off after charging the brake booster. Maybe the OFF and ON setting should be further apart? That would probably improve this.
  After trying the Dorman switch, I also ordered a
new genuine Volvo switch. I tested that too and it was exactly the same.  OFF at about 14 Hg and ON again at about 13.25 Hg. 
I then vacuum tested my old brake booster using a hand-held vacuum pump and I found, even though it was working pretty well, it was not holding and keeping vacuum quite as perfectly as it should. Then I hooked up a brand new booster and the above ON-OFF Click-Click problem continued.  Then, finally, I changed the hose plumbing arrangement and things improved (see BELOW).

If you need to vacuum TEST your brake booster, I have more info in the Brake Booster Section.

CHANGING THE PLUMBING ARRANGEMENT
I had chosen ARRANGEMENT 1 after seeing it that way in Volvo diagrams and a couple videos showing where the hoses from this switch normally go. After suffering through the above issue,
I found that someone (T8fanning in this TB forum thread),  had also installed this same pump and vacuum switch in a 240, but he had plumbed the hoses differently and it seemed to be working better for him.
So then I swapped two hoses on the switch to be like ARRANGEMENT 2 below. It seemed to work better. I can't explain why and I don't like it when something works for no explainable reason, especially when I have seen info on-line showing I had the "proper" arrangement before. But testing will continue using this new arrangement and we'll see how it continues to function.

The BELOW photos show Arrangement 2.

And I made a new video demonstrating how it's working now. 
https://www.youtube.com/watch?v=a76cz8jDZN0
I added captions so it's easier to understand (you might need to click the CC button).



Optional Retainer (clip) for mounting the above Vacuum Switch.

This retainer is Volvo PN 30665071. It was used in Volvos which used this vacuum switch.  If you need a way to mount this switch, at the time of writing this it's available new for about $5.00.


More coming later . . . .




Hydroboost Conversion for 240
If you want to keep your power assisted brakes but for whatever reason you cannot fit or cannot use a vacuum brake booster, then this Hydroboost conversion might interest you.
This has been done a couple times on a 240. I thought it deserved to be shown here in case this can be useful for any of you modded 240 owners brave enough to go this far.
If you're doing a modification like this in your Volvo, please contact me. I'd really like to hear about it.

The Hydroboost unit installed into this 240 came from a 1999 Ford Mustang Cobra.

This information does not come from my personal experience. This information comes from Aidan H. of State College, PA, and his 1990 240 wagon. He installed a massive Ford 4.6L 32V DOHC V8 from a 1998 Lincoln Mark VIII. Aidan's build thread is very detailed with a lot of photos. He offers a large amount of easy to understand explanations for many of the unusual mods he did. Aidan's reason for installing a hydroboost was there was just no room left for a vacuum booster with this humongous engine.
Aidan's build thread: https://turbobricks.com/index.php?threads/4-6-32v-240-wagon.343681.

This system uses the existing power steering hydraulic pump to feed pressurized power steering fluid to the Hydroboost unit. The Hydroboost system then uses that pressurized fluid to boost the brake pedal. The Hydroboost does not use or need a vacuum source. This is why it's the preferred system used for diesel engines or any other engine with a low vacuum source. and of course it has also been used in cars with no room for a vacuum booster, like the Mustang. If you're wondering what that external cylinder is that can be seen of any Hydroboost. It's a gas pressure cylinder that acts a pressure reservoir. It will hold hydraulic pressure in the unit after the engine stops, which can perform as a safetly device, allowing the brakes to retain some power assist for one or two pumps if the engine dies which moving.  

Aidan made a nice introduction video about the car after it was completed.
https://www.youtube.com/watch?v=InrcvRi6slk



General Hydroboost Hose Plumbing Diagram

The above diagram is focused on the Ford Mustang Hydroboost unit. Other Hydroboost units are out there and there seems to be some small differences between this one and Ford truck units. Plus there are GM and Mopar versions and also some aftermarket versions designed for custom installations. I'll show more info further down about the differences that I've found.

Note in the above diagram that there are THREE hose ports on a Hydroboost unit.  Two are high pressure ports and one is a low pressure output that returns fluid to the reservoir (this low pressure hose tees with the low pressure return hose from the steering rack hose to the reservoir). There are other hose diagrams online which show options, such as filters and coolers, if you think that's also needed.

Mounting the Hydroboost.
 
Here's are some side by side comparison photos between the Mustang Hydroboost and the 240 vacuum booster.

 
The above photo shows how the 1999-2004 Mustang Hydroboost looks when mounted in a Mustang. Notice in this photo that the master cylinder reservoir top is LEVEL and the firewall mounting plate is VERTICAL, but everything else is at an uphill angle. This style of mounting was specific and unique to the Mustang. Many Hydroboost units are mounted LEVEL in many other vehicles. It appears only a few vehicles have them at an angle.

Since it's best to mount this unit level in a Volvo, Aidan removed the mounting plate and flattened it using a press. The plate can be separated by removing a large nut (1 15/16 inch) on the back, which secures the Hydroboost to the plate. Flattening a used plate is one option. If you're willing to buy (or create) a different mounting plate, you'll find a variety of Hydroboost mounting plates online with different configurations, or make your own like discussed below.

Mounting the 240 Brake Pedal Box Behind the Hydroboost
 

The firewall bolt pattern for the Hydroboost and the existing holes for the vacuum booster are not in the the same place. Aidan drilled new holes in his firewall for the Mustang Hydroboost mounting plate.
The brake pedal box in a 240 is normally held to the firewall by the four studs on the vacuum booster. The Volvo 240 bolt pattern measures 142 x 90 mm (5.6 x 3.54 inches).


So as seen ABOVE, Aidan tack-welded four bolts into the existing holes so the brake pedal box could be bolted in under the dash.


According to https://lmr.com/products/ (source of above photo) Ford Mustang Hydroboost units came with two different bolt patterns as shown above, which are reportedly 3 1/4 inches high and 4 1/4 inches wide.
If you have some fabrication skills, you might consider making your own NEW CUSTOM MOUNTING PLATE for the Hydroboost with bolt pattern spacing of 142 x 90 mm, same as the existing firewall holes for the Volvo firewall and brake pedal box. The large center hole for the Hydroboost is reportedly 1 5/8 inch.  
 
Mounting the Master Cylinder
 

As you can see above, the 240 master cylinder has a horizontal mounting flange. Mustangs that used Hydroboost use a vertical flange. One is 90 degrees and the other is 70 degrees. The actual Hydroboost unit may be the same. Just clocked differently. A Mustang Hydroboost is not the only option, but it's the one Aidan used. There are other Hydroboosts that are mounted so the master cylinder flange is horizontal.


Aidan decided to design and make his own adapter. He found that both the Volvo and Ford Mustang master cylinder flanges had the same bolt spacing of 3.2 inches.

I added a couple more dimensions to Aidan's drawing above. It rotates the master cylinder 70 degrees.
If you're not capable of making or having such an adapter made, check online. There are existing adapters already being offered for custom Hydroboost installations that can re-clock a master cylinder.


The pushrod from the Hydroboost to the master cylinder needed to be shorter, so Aidan ground it down until it would fit just right.

Next I'll show the push rod for the brake pedal.

Here's the problem above. The Hydroboost push rod is quite different from one that will work for a 240. While there is more than one solution, first I'll show how Aidan addressed this below.


The hole in the Mustang Hydroboost push rod was 5/8 inch. Adain used a piece of 5/8 inch steel to fashion a spacer to fit in the hole. He then cut a slot in the leading edge of the 240 brake pedal arm.

This seems to work fine, however there may be other solutions that can be created to use an existing clevis and pin that might be more similar to the type used in a 240.

So there are replacement push rods that can be found for a Hydroboost, some with clevis devices that might be usable.
If you're wondering if or how the Hydroboost push rod can be removed, I found a couple videos showing how. It's pressed in and needs a little force to pull it out. Seems fairly simple to remove it.
https://www.youtube.com/watch?v=XQpiRcgBfjI
https://www.youtube.com/watch?v=eZi5O30f5GU&t=68s

Comparing a Ford Hydroboost to GM.



The above photos shown some basic differences. The obvious difference is that the GM Hydroboost is mounted in a different clocked position. The reservoir cylinder is below the unit and master cylinder flange is horizontal.  The length of the GM unit may be a little different, but that's hard to tell from a photo.

Something different to stare at and wonder.

For mostly entertainment purposes. This is a GM Hydroboost that's been mounted REMOTELY in the trunk of a 1966 Ford Fairlane, which was owned by Dick Hedman (son of Bob Hedman of Hedman Hedders). There was a pretty good reason for doing this. No room under the hood. You can check the car out at the below link. The brake pedal pushes a small master cylinder under the dash, which feeds to the slave cylinder in the trunk, which pushes the Hydroboost, etc. The instrument cluster opens or folds out to view the fluid level. Check it out. You won't be disappointed: https://bringatrailer.com/listing/1966-ford-fairlane-29/




iBooster Conversion for Volvo
If you want to keep your power assisted brakes but for whatever reason you cannot use a vacuum brake booster, then this ALL-ELECTRIC conversion info might interest you.

Here's an article detailing how to install an electric brake booster from an EV in a 122. The process would not be very different for a 240. Electric brake boosters are being used in performance applications with low manifold vacuum, hybrid and electric car conversions or to save on space in the engine bay.
https://www.evcreate.com/installing-the-ibooster/


and here's a video from SuperfastMatt.
https://www.youtube.com/watch?v=SRZ8XDNz2vU



iBooster versus Hydroboost
https://www.youtube.com/watch?v=udVos52u2t8



Compact Remote Electric Booster
This is an electric REMOTE brake booster. It's remote because it can be mounted in another location away from the master cylinder. This is useful if your firewall lacks the space for a vacuum booster or an alternative booster, like those above. In the below image and video, it can be seen mounted BEHIND an inner fender.   

Dimensions are 7 inches long x 5 inches wide x 8 inches high.

The above images come from the Jegs instruction Guide, which can be found at:
https://www.jegs.com/InstallationInstructions/500/555/555-631252.pdf

Hot Rod Build Shop Installation Video
https://www.youtube.com/watch?v=iiS7p9zYBpU


Product video from Speedway Motors
https://www.youtube.com/watch?v=jqMh_iPVokY&t=69s


At time of writing it's available from Jegs or Speedway Motors.
Speedway Motors link:
https://www.speedwaymotors.com/Compact-Electric-Brake-Power-Booster-Master-Cylinder-Disc-Drum,9643.html






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