Volvo 240 Hydraulic Clutch Info.

2 4 0 T U R B O . C O M
D A V E ' S V O L V O P A G E

Volvo 240 Hydraulic Clutch
and Stuff

UPDATED: April 1, 2023 CONTACT

D O M A I N S

So I thought I would put together a page to keep track of the hydraulic clutch parts I have put in my 240 and all the other things I've learned about this stuff.
Useful info. I hope it will help.
Nothing here is for sale (at least from me).

260 FAG Master Cylinder	Clutch Hose
Components Diagram	Bell Housing
Tilton Master Cylinder	Tilton Master Cylinder #2
Hose for Tilton MC	Failed Bent Pedal Box

Let me back up a bit before I get to my hydraulic clutch stuff.
This is the "heavier" 8.5 inch clutch I put into my 245 way back in 2004 when I first installed a T5 transmission into my old 245 Turbo with the 2.6 liter stroker. This clutch was "custom" made from Clutchnet in SoCal. It failed because it had major slipping in freeway gears under boost. So Clutchnet made a custom much stiffer one.

This new much heavier pressure plate was assembled using two standard spring sets stacked together. Very simple idea.
The result was a clutch with 3000 lbs of clamping force. It was so successful that later Clutchnet began offering it to the public. The friction disc I used was nothing special. Simple organic type.

The reason I mention all this is because it will help you understand why this is a heavy clutch and it had a tendency to stretch and eventually snap clutch cables.
And long before a cable would snap, it would require adjustments often because of all that stretching. Not good stuff.

I know someone who even went to the trouble of modifying his 240 clutch pedal to accept TWO clutch cables.

So back a number of years ago when I installed the T5 trans in my 242, I went with the same clutch.
I know there are better clutch setups available nowadays. Lots more cools stuff has become available over the years because of the increasing popularity of these cars. I'll get around to trying a better one someday. For now, this is what I have.
After a few snapped cables, I knew I needed to upgrade to hydraulic.

Here are some CABLE CLUTCH diagrams from the 1981 New Car Features book.

Here is a diagram for the HYDRAULIC CLUTCH.

This image above suggests there is "no play to adjust." This is true with regard to the pedal, but there is some adjustment available by spacing the clutch pivot ball closer to or further from the bell housing. The clutch pivot can be seen in this page HERE.

This conversion from Cable to Hydraulic was completed in 2011.

INTRODUCTION OF THE 260 HYDRAULIC MASTER CYLINDER
This is the Volvo 260 clutch master cylinder I used, Volvo PN 1205729, manufactured by Fag. Aftermarket may be available as Centric PN 136.39000.
It was used in the manual trans 264 in North America and in all manual trans 240 models in the UK and Australia because they were right hand drive. It was still available new when I started buying these parts in 2011. It still may be available. You might also find them used and I think rebuild kits are still available if you do.

The inner bore/piston diameter is 19 mm (0.75 inch).

The hose port is 12 x 1.0 mm Inverted Flare (double flare). It uses a hose like this photo.

So then I needed a clutch hose to mate the MC to a Slave Cylinder.
Back in 2011 I was able to locate a USED hose (like this one shown below). It had a hard line beginning at the master cylinder and transitioned to a flexible hose further down.
I also chose the same slave cylinder seen in this first photo. It was originally made for a 740, but it fits perfectly in the 240. Note the different looking clutch master cylinder. 740s used a clutch master cylinder without it's own reservoir. Instead this cylinder receives fluid from the brake MC reservoir, as you can see in the second photo.

The length of this 740 clutch master cylinder is much longer than one for a 240. I thought it would be difficult to fit in a 240 (until I later saw this second photo above of someone who did it).

Be aware that the body of this 740 clutch master cylinder is longer than the 260 FAG MC, so it will be a fairly tight fit in a 240. The hard line should be made to turn quickly so it clears the strut tower.
This 740 Clutch MC is known as PN 8601785 (also 1273680, 1330248, 1330249). The piston/bore is 19 mm (0.75 inch) for the master cylinder (same for the slave cylinder).

If you decide to have a custom hose made by your local hydraulic hose shop, the original length of this pictured hose above is about 38 inches, but anything above about 30 inches will fit just fine in a 240.

The inner bore/piston diameter for both the 740 clutch master cylinder and slave cylinder is 19 mm (0.75 inch).

Building your own clutch hose.
An original Volvo 264 hydraulic clutch hose is not easy to find.
This image below is a banjo adapter that can be found online. It's thread size is 12 x 1.0 mm and it will fit the master cylinder. It uses the AN -3 end for the hose. Search for "Steel M12x1.0 to 3AN banjo fitting".
Optionally you can choose -4 AN hose, but for this info I will use -3 AN. Using a banjo fitting on the MC can help with a tight fitting master cylinder that has very limited room for the hose.

Using adapters shown here you can either seek out a pre-made hose or build one yourself. A proper length can be 30 to 36 inches. If you buy the parts to build one yourself, choose a hose type that is rated for high pressure, such as this: https://www.pegasusautoracing.com/productselection.asp?Product=3260 or https://www.summitracing.com/parts/aer-fcc0303
These Stainless Steel Braided PTFE Brake & Clutch Hoses can handle 3000 psi.

Here are some hose ends in -3 AN size: https://www.pegasusautoracing.com/productdetails.asp?RecID=4154. Pegasus PN 3261-3-00 straight 3AN hose end.

THIS GUIDE WILL HELP IF YOU WANT A FLARED HARD LINE AT THE MASTER CYLINDER
If you prefer a hard line like this below, you'll need to flare the pipe. So you'll need a flaring tool or someone who can flare brake line. This hard pipe is the same as brake line, but normally this clutch line is larger than typical 3/16 inch (4.75 mm) brake line you have one your 240, although you CAN use 3/16 inch if you like.
A larger size pipe can be 6 mm brake line.
The flare type needs to be Inverted Flare (double flare), because that's what this MC needs. That fitting in this photo below is 12 x 1.0 mm for Inverted Flare (double flare).

If you use 3/16 inch brake line, you can use this flare fitting fitting at the master cylinder (1 needed): https://www.belmetric.com/double-flare12x1df475.html.
If using a larger 6 mm brake line, you can use this one (1 needed): https://www.belmetric.com/double-flare12x10df600.html.

Then on the other end of the hard line, which will transition to a flexible line, you can use a similar fitting, except in my opinion this end should be flared as a bubble flare.
That would mean this fitting is used (if using 3/16 inch line) (1 needed): https://www.belmetric.com/bubble-flare12x10bf475.html.
Or this one (if using 6 mm line) (1 needed): https://www.belmetric.com/bubble-flare12x10bf600.html.

This fitting can then be mated to an adapter, which will adapt the 12 x 1.0 mm flare fitting to an AN -3 hose end.
This one will do it (1 needed): https://www.summitracing.com/parts/cst-sbh8069.

So then the flexible hose will be AN -3 high pressure hose like this (3 feet): https://www.summitracing.com/parts/aer-fcc0303
with a hose end like this on each end (2 needed): https://www.summitracing.com/parts/aer-fbm1100.

Here's a useful video showing how to assemble a hose like this.
https://www.youtube.com/watch?v=5tdsgZ-KfWI

Here are some adapters that will fit the 740 slave cylinder, which has M12x1.0 threads. The hose side will use either AN -3 or AN -4 thread. You can search for "Steel M12x1.0 to 3AN adapter" or "Steel M12x1.0 to 4AN adapter".
Or something like this: https://www.summitracing.com/parts/ear-592053erl
You should use a brass sealing washer on the M12 side (the side going to the slave cylinder).
Or as a better option that I used, a metal-bonded sealing washer shown below.

This is a metal-bonded sealing washer below. It has a rubber o-ring embedded in it. It's generally used when a flare fitting is not used, such as on the M12 end of this adapter above.
McMaster Carr has these washers: https://www.mcmaster.com/#standard-washers/=1blhle3, click "Sealing Washers," then "Metric High-Pressure Metal-Bonded Sealing Washers." Your local hydraulic hose shop may have them too. They can also be found at Pegasus Racing, called Stat-O-Seal Sealing Washers: https://www.pegasusautoracing.com/productselection.asp?Product=3245

The custom clutch hose I had assembled in 2017 by a hydraulic shop can be seen a bit further below or CLICK HERE.

The 740 hose and slave cylinder are made to be a perfect fit on the typical M46 bell housing.
The circular mount on an M46 (or M47) bell housing is designed to hold either the cable end or this slave cylinder. This slave is Volvo 740 PN 8601783 (older PN 6843913). It's still available from a number of sources.

Be aware there are some very early Volvo bell housings that have a different configuration and use a different slave cylinder. This type can be seen in the below early diagram. You're on your own with that type slave, since I have no useful info on that.

This 740 slave cylinder has a port that is threaded 12 x 1.0 mm. It's machined at the bottom for a bubble flare, so if you prefer, you can use a 12 x 1.0 mm Bubble hose end or adapter fitting. The face of the port is also machined flat, so you can optionally use a 12 x 1.0 mm fitting that accepts a sealing washer (brass, aluminum or metal-bonded sealing washer). The second photo below shows what the original hose end looks like for the 740 slave cylinder. the thread is12 x 1.0 mm Bubble Flare. It's pictured next to a 240 brake line for comparison.

And you'll need this external snap ring (AKA: external circlip, retaining ring) to keep the slave cylinder locked in the mount. It's Volvo PN 914463 (part number for 740 part). Inside diameter is 30 mm (1 3/16 inch or 1.187 inch).

CAUTION: Be careful of this little PLASTIC END CAP on the slave cylinder push rod.
If your clutch fork has a HOLE in it, as this one does pictured below, where the plastic end on the push-rod pushes, you could experience a failure like I did.

One minute you have a nice working clutch. The next minute your pedal goes to the floor! Because of THIS.
The white plastic end cap sheered and the push-rod went right through the hole in the fork.

So I then drilled that hole out and installed a large socket head (Allen head) bolt in there. Now the end of that rod rests in the center of that socket head.

Here's a useful diagram showing hydraulic clutch components.

Not all part numbers listed here will be found to be the current or latest part numbers. If you find information that you can help to improve in this page, please let me know.

Converting from a cable to hydraulic clutch requires that you have a compatible bell housing.
These TWO photos below show a later type M46 or M47 bell housing. One part that gives it away as a later type is the opening at the top of the bell housing (top-left in the first pic) for a crank position sensor, which came on 1989 and later cars. That's not really important for this information. Just a bit of trivia.

You won't necessarily need a bell housing that has an opening for a crank position sensor unless you're using an engine management system that requires it, such as LH 2.4. The important thing is that the bell housing has the second pivot ball mounting hole for a hydraulic clutch FORK. There are some early M46 bell housings that do not have this second mounting hole.

Here are some close-up images of the hole for the hydraulic pivot ball.

There is more than one style of pivot ball. Below: One is short and one is tall. The threaded hole on the rear is M8-1.25.

Comparison: Cable and Hydraulic Clutch Forks.
The top clutch fork is a typical cable type. The bottom one is a typical hydraulic type from a 740. Any typical 740 clutch fork is perfect for this project.
Part numbers that should work: 3549983, 1220763.

I found a used 260 hydraulic clutch pedal and fitted it into my existing manual trans pedal box.
A hydraulic clutch pedal is about 50 mm longer than the cable pedal because it mounts in a different set of holes in the pedal box. The hydraulic pedal holes are higher up. The holes will normally already be in the pedal box.

Here is where the holes are for mounting the hydraulic pedal.

There are some Turbobricks threads in which people have made their own hydraulic pedals or modified a cable type pedal to work. That sort of work was beyond my skills.

Here's a thread about one that was custom made: https://forums.turbobricks.com/showthread.php?t=326370&page=6

As of May 2018
STS Machining is offering newly made aluminum hydraulic clutch pedals:
https://www.stsmachininginc.com/products/240-hydro-clutch-ped

My Master Cylinder Change in 2017

After about 6 years of use, the new Volvo 260 Fag master cylinder shown here began to fail. The piston seal began leaking fluid out of the back when pushing on it.

This might have been due to the heavy clutch, but it could also be because this was a 30 plus year old NOS part when I bought it. I could have rebuilt it, but I thought the chance of this happening again was high. So I decided to try a different master cylinder. There are a number of choices. I'll show you a few I considered below.

Whichever master cylinder you choose, be sure to choose the correct inner piston size. Most aftermarket master cylinders will give you several size choices.
The Volvo Fag 260 MC has a 0.75 inch (19 mm) piston. That's the size I would be looking for (but if you read further down, you'll find out I later changed my mind for my clutch).

A master cylinder like this one below from Wilwood may be a good choice.

It's certainly short enough to fit in a 240 and it's very similar to early Volvo master cylinders used in Amazons, however I did not care for the hose outlet being on top like this. It makes bleeding more difficult than something with a hose sloping downward.
When bleeding a hose that rises above the master cylinder, air will get trapped in there. So when bleeding, it will be pretty much impossible to get that air out if you have someone pushing the pedal while you're under the car opening the bleed valve. It can easily be done with a power bleeder which has the ability to push a lot of fluid through the hose under pressure to overcome that big air bubble.

If I had chosen one like this above, I think I would have put a 90 degree fitting on there or maybe a banjo fitting if it will fit.
A good benefit of this master cylinder is that it offers an advertised stroke of 1.4 inches (35.5 mm). This is close to the Volvo Fag 260 MC, which has a stroke of 1.3 inches (33 mm). The TILTON MC below only has a 1.1 inch (28 mm) stroke.
The STROKE info became more important later. You'll see if you keep reading.

Here's a comparison photo above of three master cylinders.
Left side:	Original Volvo 260 Fag.
Middle:	Tilton 75 Series. Definitely a compact one. Wilwood has a nearly identical model called Wilwood Compact.
Right side:	Wilwood. This one is sadly too long to fit in a 240. The hydraulic hose end of the master cylinder actually hits the inner fender and that's where the hose needs to go. Possibly it could fit if a banjo fitting was put on the end and maybe a hammer used on the fender. I didn't try that, so I don't know for sure.

I chose the middle Tilton 75 Series. This one has a .750 inch (19 mm) piston.
Soon after installing it I discovered that there was a new problem. There always is, isn't there.

The 240 firewall sheet metal (just above where the master cylinder mounts to the firewall) interfered with the reservoir. It's because the reservoir on this style master cylinder is positioned so far to the rear and so close to the firewall mounting flange. Basically the reservoir hits the firewall before the mounting flange does. PHOTOS coming up further below.

The port is threaded for 3/8-24 female, same as AN -3.

One solution for this interference could be a remote reservoir. I didn't seriously think that was a good option, however after completing my project I found this photo below of a Wilwood compact master cylinder with a remote reservoir. So it seems it's been done. More on the thread where this photo came from can be found at https://forums.turbobricks.com/showthread.php?t=335335.

Or I could have used a 740 brake master cylinder to feed the clutch MC remotely. Again, I didn't know about this option until later.

FIXING THE FIREWALL CLEARANCE ISSUE with SPACERS:
So my solution was to use a couple 1/2 inch thick round spacers and some longer bolts I had on hand. Not the most elegant solution, but it gets the job done just fine and mounting at the firewall is still very solid. Problem fixed.
I had originally hoped to find a 1/2 inch spacer shaped similar to the mounting flange so I could move this master cylinder 1/2 inch forward. Such a spacer did not exist when I was searching.

Then it was time to have the new hose made. I took the master and slave cylinders down to a local hydraulic hose shop, along with the adapters I had.
Keep in mind that most hydraulic hose shops are there to make hoses for heavy equipment. They may not be experienced with automotive or hot rod stuff. There are a number of ways to make a hose for these components. Lots of options exist. If you know specifically what fittings YOU want, discuss that with them. Try to be patient and have as much info for them as possible.

Hose detail: Tilton Clutch MC:
The Fag-Volvo 260 MC I previously used and the 740 slave cylinder both have a thread pitch of 12 x 1.0 mm female. Now I have an MC with a different thread.
This Tilton MC has 3/8-24 female threads, which is the same as AN -3.
The port outer face is machined flat in case you want to use a banjo fitting or an AN -3 fitting which uses a sealing washer. Those are options. I went a different route.

The Tilton MC came with some adapter fittings. One was that gold double male AN-3 flare fitting in the photo above. The hose shop I went to had commercial JIC fittings and high pressure -4 Golden21/ISO 3000 psi flexible hose. They used that gold AN -3 double male flare fitting along with another adapter fitting they supplied, which stepped up the AN -3 to AN -4. Then they mated a new hose end to the AN -4 hose. This new hose end was a 45 degree JIC (AN -4) female swivel fitting, which can be seen above. That completed the MC end.

Hose detail: 740 Slave Cylinder:
On the slave cylinder end the hose shop supplied a Male JIC 7/16-20 (equal to AN -4) to 12 x 1.0 mm O-Ring adapter, which is shown below. The 12 x 1.0 mm end goes into the clutch MC. The O-Ring I used was a metal-bonded sealing washer.

The above adapter would then mate to a new hose fitting they crimped onto the AN -4 flexible hose. This new hose fitting was a JIC 7/16-20 (equal to AN -4) STRAIGHT female swivel fitting, which can be seen in the hose photo above.
The total length of the new hose when completed was about 38 inches.
Cost was about $60.

This is a metal-bonded sealing washer.
It has a rubber o-ring embedded in it. It's generally used when a flare fitting is not used, such as on the M12 end of this adapter. McMaster Car has them: https://www.mcmaster.com/#standard-washers/=1blhle3, click "Sealing Washers," then "Metric High-Pressure Metal-Bonded Sealing Washers." Your local hydraulic hose shop may have them too.

This clutch push rod needed some changes.
For my use it needed to be shortened almost 1/2 inch compared to when it was used with the 260 master, even with the 1/2 inch spacers at the firewall shown above. The threads on this thing allow for a small adjustment, but for the adjustment I needed, that forward rod had to be shortened a small amount (maybe 1/8 inch) using a bench grinder.

Installation completed.

To those of you who didn't believe me that spacers were needed to fit this master cylinder/reservoir combo, have a close look at this photo. Yes, that is the master cylinder WITH spacers.
The reservoir cap is almost touching the firewall.

Master Cylinder Change
Update: June 2017

I believe the piston stroke for the Volvo 260 Fag master cylinder is about 1.3 inches (33 mm). The Tilton 75 Series MC with 3/4 inch (19 mm) bore has a stroke of only 1.1 inch (27.94 mm). This presented a problem in my car and it meant I was not getting as much pedal travel as before. So the clutch wanted to disengage very close to end of the pedal travel near the floor. I didn't like that. I needed a bit more stroke, but the Tilton 75 master cylinder is not available with a longer stroke.

The Wilwood version is the same. So I changed to a Tilton 75 with a larger bore, 13/16 inch (20.64 mm) bore. The new one is the fatter MC one on the right below.
I was a bit surprised to see the difference in the much bigger body design. Adding that extra 1/16 inch (1.59 mm) to the bore adds about 17% more volume in the stroke. It's equal to increasing the stroke from 1.1 inches to 1.29 inches, which virtually gives it the same as the Volvo FAG master. That corrected the problem.

If you can add to any info in this page, please email me.

When it comes time to bleeding brake or clutch hydraulics, nothing beats the Motive Power Bleeder.
I won one of these many years ago at a Davis Volvo Meet raffle and it has served me well for years and years.
DIY bleeding with no need for a helper. Perfect.
It's about $50 for those who aren't raffle winners.

RESOURCES:
AN Thread Wikipedia: https://en.wikipedia.org/wiki/AN_thread
Automotive Fittings Explained: http://www.speedwaymotors.com/the-toolbox/automotive-fittings-explained/28780

Useful discussion treads: https://forums.turbobricks.com/showthread.php?t=100636
https://www.turbobricks.net/forums/showthread.php?t=149175
https://www.turbobricks.com/forums/showthread.php?t=234399
https://forums.turbobricks.com/showthread.php?t=325285
https://www.turbobricks.org/forums/showthread.php?t=320417

Fixing a Bent or Mangled
Clutch Pedal Box
(twice!)

Back in 2009 I thought my clutch cable must be stretching because my clutch kept going out of adjustment. I was paranoid that it would snap in heavy traffic somewhere, so I got a new cable and pulled out the old one. When I compared the two together, they were identical . . . no stretching to be seen. Then, while installing the new cable, I found something strange.

PHOTO BELOW: I could see that the metal framework for the pedal box was seriously bent. The pivot for the pedal was being pushed closer to the firewall. This explains why clutch engagement kept moving closer to the floor, making it seem as though the cable was stretching.

After I pulled out the pedal box, I could see the damage was pretty serious.

So after straightening the metal walls, I needed to reinforce the metal to keep it from doing that again. You can see here I added some steel sheet metal to strengthen that side wall.

I used some clip-on barrel nuts (also known as U-nuts) that I got from McMaster-Carr, PN 95210A150.
Thread pitch is metric: M6 x 1mm. These are made for a panel thickness of 0.8 to 4 mm.
The bolts I used are typical metric bolts with a 10 mm hex head that you'll find in your 240. If you don't have any, McMaster- Carr does: PN 98093A436, M6 x 1mm, 16mm long with flange head.

Then in 2013 while pushing in the clutch pedal I felt a SNAP.
Then the clutch pedal was suddenly very crooked as you can see here. I had already switched to a hydraulic pedal before this happened.

After pulling out my instrument cluster, I could see this welded captive nut in the cowl had been ripped out of the sheet metal.

I didn't have a welder (or welding skills) and I didn't want to take the car somewhere to be welded after pulling it apart. So i removed the dash and AC vents and I made a steel plate and carefully bent and fitted it so it would fit up under the cowl.
I took the plate to a welder and had that nut welded on.

Then I drilled holes and inserted threaded inserts I bought on-line so it could be bolted VERY SECURELY to the cowl and it would be very STRONG.

Here's the pedal box I was using on the right that got BENT.
The bend near the firewall part happened when the captive nut broke. But since these pedal boxes are not really what I would call sturdy, I decided to do a better job of reinforcing it before putting it back in.

Here we go. I added some more serious bracing this time.

This view is of the side that faces the driver. That plate comes off before installing the pedal box, since there are fasteners that you need to reach behind it. Then that plate can be re-installed.
This plate is overkill and probably not really all that necessary.

Here is an in-progress photo looking through the instrument cluster opening. The newly reinforced pedal box is being bolted in and that removable plate has been removed.

Here I have completed the installation and the front plate has been installed.

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