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Turbo Oil Drain Hose for Volvo Turbo Red Block
Using a Yoshifab Fitting
When Volvo designed
the 240 Turbo engine they used a rigid steel drain
pipe for the turbo oil return (same
design for later 740 Turbo and 940 Turbo). The
lower part of the pipe was designed to seal into
the hole in the block. Despite having a rubber
o-ring on the pipe, these tubes usually leaked
at the block.
If you fit a non-original turbo
like I did (Mitsubishi TD04HL 15G), you'll probably find the rigid pipe
no longer works. I was using a cobbled together
pipe for years.
I'm happy to 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
This new fitting was really good
news to me because I really hated the drain tube
I had cobbled together (BELOW) to fit my Mitsubishi TD04HL 15G
turbo (from an 850 Turbo). I installed
this turbo to a late model (90+) exhaust manifold. Using this turbo
meant a standard metal oil 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 silicone
construction). Itfailed at least
one other time over the years (second photo).
Silicone hose is not designed for such continuous heat and
I just knew it would eventually fail again.
<<<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 an
adhesive to seal and secure the fitting.
The top of the fitting is threaded for a standard -10 AN
racing hose fitting that you can buy
anywhere. NO DRILLING OR TAPPING IS NEEDED. NOTE: This only works for factory turbo red-block engines (B21FT, B230FT, etc).
do not have this existing hole for the oil
drain. The ID of this drain hole is reported to be 25.15 mm according
If you have a B21F, B23F or B230F block (with NO HOLE already drilled), then this is
obviously not a direct fit. You could certainly drill a hole.
The size of that hole is not known to me. Anyone know?
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. PTFE 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 here: https://www.summitracing.com/parts/SUM-2201010. You
can choose whatever AN hose you prefer. PTFE hose is rated for higher
temps, but is not as flexible as a rubber core hose, such as Aeroquip Socketless that's discuss further below.
AN RACING 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).
Yes, it's that simple!
<<< These are Tube
Ferrules. One of these goes into the above hose
end fitting. Hose end fittings like this are re-usable,
but 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 get crushed
against the hose liner during assembly and the old ferrule is
NOT reuseable. Replacement tube
ferrules are available. The -10 AN fittings
above use .625
inch ID cone 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
Mitsubishi TD04 turbo.
Here is my new
assembled drain hose ready to go in.
Overall length for my new hose was 16 inches . .
. . . however it
could have 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
If you need something more
flexible, have a look at the below alternatives.
Keep in mind that if your
engine has a later (740/940) style oil filter
mount like shown below, then your hose may need a
45 degree fitting at the end going to the block, or it might interfere with the oil filter.
NON-PTFE ALTERNATIVE: If you're looking for something
perhaps a rubber type hose will suit you
Yoshifab will tell you they prefer
This is 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 to 300 degrees Fahrenheit.
More general info
can be found here:https://www.jegs.com/p/Aeroquip/Aeroquip-Socketless-Racing-Hoses/750321/10002/-1
Oetiker Clamp While no clamps are
technically required for Aeroquip Socketless
recommends adding a clamp when using this hose,
especially if it will be carrying high pressure
oil. A simple Oetiker Clamp or Pinch Clamp
is the recommended type and may be easily found
at Summit Racing, Grainger or other parts
a good resource for general AN hose and
fitting sizes, dimensions, thread pitches,
It helps explain many different types of
AN fittings and standard thread pitches used.