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Drain Hose for Volvo Turbo Red Blocks
When Volvo designed the 240 Turbo engine they used a rigid steel
drain pipe for the turbo oil return (same design for later 740
940 Turbo). The lower part of the pipe
was designed to seal into the hole in the block. Despite having a
o-ring on the pipe, these tubes usually leaked at the block. If
you fit a different turbo like I did, you'll probably find the rigid
pipe no longer works. I was using a cobbled together pipe for years.
report that Yoshifab has
brought the red block drain pipe into the 21st century
by introducing a new custom hose
fitting that fits into the existing hole in the block and allows
you to use modern racing hose and
fittings for a much
better drain system.
This was really good news to me because I really hated the drain tube I
had cobbled together to fit my Mitsubishi TD04 turbo (from an 850
Turbo). I installed it to a late model
(90+) exhaust manifold, but this turbo meant a standard metal drain
pipe would no longer
fit. The pipe I made was functional, but I didn't
trust the soft hose there in the middle due to the extreme heat it was
subjected to (even though it was reinforced
It failed at least one other time over the years (see photo).
Silicone hose is not designed for such heat and I just knew it
would eventually fail again at a bad time.
<<<The fit is so
precise that the instructions call for this fitting to be placed in the
freezer before tapping it into the hole. Yoshifab supplies
adhesive to seal and secure the fitting. The top of the fitting
for a standard -10 AN racing hose
that you can buy anywhere.
NOTE: This only works for factory turbo engine blocks (B21FT, B230FT,
Non-turbo engines do not have this hole for this oil drain.
AN HOSE TRIVIA NOTE AN racing style hose
internal dimensions are measured in 1/16th of an inch increments.
-8 AN is 8/16th of an inch ID (1/2 inch). -10 AN is 10/16ths of
an inch ID (5/8 inch).
I bought a 3 foot section of hose to go along with the
fittings. I chose PTFE core
stainless steel braided hose, which has a Teflon inner core.
This hose is designed for hot, high-pressure oil and has high
temperature rating of 400 degrees Fahrenheit.
This item: SUM-2201010
Hose, PTFE, Braided Stainless Steel, -10 AN, 3 ft. Length. Found
These are Tube Ferrules. One of these goes into the above hose end
Hose end fittings like this are re-usable,
it's important to
note that if you
disassemble one after it's been installed, you must
replace the TUBE FERRULE before re-installing. The
ferrule is designed to
crushed against the hose liner during assembly and the old ferrule
reuseable. Replacement tube ferrules are available. The
-10 AN fittings above use .625 inch
style ferrules like those found here: https://www.summitracing.com/parts/rus-620505/.
I found this -10AN
Aluminum Turbo Oil Return Drain Flange on eBay to fit my
Here is my new assembled drain hose ready to go in. Overall
length for my new hose was 16 inches . . . .
<<<. . . however it could
been shorter by at least 2 inches and it would still fit just
fine. Now I have piece of mind that if something is going to
break, it will not be that drain hose.
This PTFE hose is rated at 400 degrees Fahrenheit, but a disadvantage of using this hose is
that's it's pretty RIGID,
which can make it difficult to make
sharp bends. If you need something more flexible, have a look at
the Aeroquip Socketless below.
<<< Keep in mind that if your engine has a later
(740/940) style oil filter mount, such as shown here, then your hose may need a 45 degree fitting
down at that block fitting.
If you find the PTFE hose is a bit too
rigid and you're looking for something more
flexible, perhaps a rubber type hose will suit you better. Yoshifab will tell you they prefer
using Aeroquip Socketless Hose
(pictured at left).
That's a rubber core hose that uses special barbed hose fittings.
Assembly is much faster and
easier and routing them is easier because they're more flexible.
Aeroquip Socketless hose is rated at 300
degrees Fahrenheit. More general info
can be found here:https://www.jegs.com/p/Aeroquip/Aeroquip-Socketless-Racing-Hoses/750321/10002/-1
While no clamps are technically required for Aeroquip Socketless hose, Yoshifab recommends adding a clamp
on this hose, especially if it will be carrying high pressure
oil. A simple Oetiker Clamp
or Pinch Clamp is the
and may be easily found at Summit Racing, Grainger or other parts
suppliers. Here are some videos on
installing Oetiker clamps: https://www.youtube.com/watch?v=W1qTw8OmbMA https://www.youtube.com/watch?v=Xn8iv10LV5A
good resource for
general AN hose and fitting sizes, dimensions, thread pitches, etc. It
many different types of AN
fittings and standard thread pitches used. http://fuelab.com/tag/an-thread/