[Vwdiesel] need oil return line thread...(long summary)

[Doyt W. Echelberger]

Regarding "turbo oil return line, VW part number 068-145-736-A:"   Since 
this foot-and-a half long part lists at $280, and isn't really available 
anywhere that I looked, I'm documenting the fix for anyone that will 
eventually have to do the same thing. Maybe this belongs on a web site:

Because it was obviously spraying oil all over the firewall, I took the 
turbo oil return line off while I had the head off the 1.6 TD block in my 
85 Jetta, prior to installing a new head gasket. It is practically 
impossible to get this line off any other way. It was badly rusted and 
obviously leaking significant quantities of oil, which ran down the 
firewall and that face of the engine.

Suggestion: Try to save the very thin metal gasket between the turbo and 
the return line. Mine came off whole, stuck to the return line. I soaked it 
off with brake cleaner.

I used brake cleaner and a wire brush to remove the crust of burnt-on and 
caked oil residue on the short end of the oil return line that bolts to the 
turbo.  The cleaning process exposed lumps and bumps of flaking rust, which 
I removed down to bare metal with the blade of a short screwdriver, then 
Dremeled the bare metal smooth with sandpaper wheels. This left the tube 
looking like new, except for several dozen pin-head sized pits of blackened 
corrosion.

Next I tested for leaks: Filled a 5 gallon pail with water, stoppered the 
long end of the return line, and pressed a rubber-ended air chuck into the 
opening of the short end of the return line. Holding the entire return line 
under water, I eased a very short burst of compressed air into the line, 
and observed a stream of bubbles coming from an almost invisible pit in the 
short end tube, about 1/8 inch from the crimp fitting. No bubbles came from 
the braided area, so I concluded that there was only the one one leaker. 
This surprised me, as I had expected the braided area to be the source of 
the leak.

Marked the leak-point and assembled the materials for plugging it:  One 
tube of high-temp epoxy putty from NAPA, good to 500 degrees F; one 
stainless steel hose clamp of the screw-on variety, about a quarter inch 
wide; a pint of 91% isopropyl alcohol; screwdriver to tighten the hose 
clamp; old wash rag to dab on the alcohol.

Dremel the inside surface of the stainless hose clamp, to roughen the metal 
and give the epoxy a bite. You already have roughened the surface of the 
leaking tube.

With the clean wash rag, swab the bare metal of both the return line and 
the hose clamp with alcohol, removing all traces of oil.  Shake off excess 
alcohol and blow it dry. Do it again if you have any doubts about even 
slight traces of oil. Be sure everything is dry before starting the epoxy.

Unscrew the stainless hose clamp and fit it around the leaking metal tube. 
Tighten the clamp until it takes the shape of the tube. Loosen the clamp 
and slide it away from the mark that ID's the leak point. Once you start 
the epoxy cycle, you don't want to spend any time fitting the clamp.

Cut off a short inch of the epoxy putty. Knead it for twice as long as you 
think necessary to mix the resin and hardener, and apply the mix to the 
leaking section of the tube with heavy finger pressure, smearing the putty 
onto and into the roughened metal of the tube, making a coating about 1/16 
inch thick that covers half the length of the tube.

Slide the previously fitted loose clamp over the putty-covered section of 
the tube, centering the clamp directly over the leak point. Tighten the 
clamp into the putty as far as you can take it. Putty oozes out all around 
the clamp. Smooth that putty back over the band of the clamp. Add some more 
putty and hide the clamp band with it. Work the putty into openings in the 
clamp, using a flat blade screwdriver. Form the putty with your fingers 
until it completely covers the tube.  The putty cures in about 5 minutes, 
so do everything mentioned above in that time frame.

After it cures, cut off another length of putty and knead it, and cover any 
remainder of the short tube, working the new putty into a seamless covering 
between the turbo fitting and the crimp of the braided section.  Let it 
cure for a few hours, or a day if you have time. Sand it smooth if that is 
your thing. Then put it back on the engine and run it for another 20-30 
years, to test the fix :~) Or, spend endless days and countless dollars, 
searching for VW part number 068-145-736-A.........a Unicorn-like and 
unobtainable nos part, which theoretically exists somewhere in the USA, in 
a VW parts warehouse, maybe.


Doyt Echelberger