replacing seals on turbo oil return pipe - PeachParts Mercedes-Benz Forum

jamesNB · #1 12-29-2009, 03:45 PM

I've got some oil leaking from the oil return pipes from the turbocharger on my 1979 300SD so I'm planning to replace the o-rings and the seal at the oil pan. I can't seem to get to the two bolt that attached the upper pipe to the turbocharger body. I can get a socket on them but I can't get any leverage to loosen them.
1. Do I have to remove the turbocharger to access the two bolts?
2. Is removing the turbo a big deal?
3. The manual mentions using "heat resistant nuts and bolt" to reattach the turbo to the exhaust. What are these? Stainless? Black Oxide?
4. Can I reuse the 30 year old nuts and bolts?
Thanks

SirNik84 · #2 12-29-2009, 04:00 PM

I was able to get those bolts off with a 3/8th wratches. maybe PB blaster them and try it again after a while.

If you do pull the turbo you can reuse the nuts. I've done that. someone will chime in if its a no-no but i've taken my turbo off twice now, and no problems with the nuts.

It may be harder to pull the turbo them to get the tube off, those exhaust nuts like to bond together with rust.

Good Luck.

compress ignite · #3 12-29-2009, 07:49 PM

The directions say to "Always use heat resistant nuts and bolts"...
Well O.K. ,It doesn't say you cannot reuse the very same nuts and bolts.

AND Almost Always , If the occasion to Alert you to the Possibility of a
Purchase Opportunity of NEW MERCEDES PARTS presents itself the Factory
will not let you down.

My Favorite Recalcitrant Nut/Bolt RELEASE agent:

AeroKroil (Apply and let part(s) sit overnight or longer)
http://www.kanolabs.com/

charmalu · #4 12-30-2009, 02:17 AM

The 2 bolts are 13mm. I think I uses a 3/8 wratchet, a swivel, and a extention. It`s a tight fit, pita to brake loose. once I did, then I used a 1/4 in wratchet to take them out.

That kroil is some good stuff. forget PB Blaster.

I have reused the 3 nuts that hold the down pipe on, and have never had a problem with them. I think they are copper.

Charlie

Hit Man X · #5 12-30-2009, 02:43 AM

If you are pulling that, there is some sort of check valve in there that you should consider replacing.

Junkman · #6 12-30-2009, 11:10 AM

There is a gasket set that includes turbo gaskets down to the manifold. The local NAPA price matched the exact same set when I told them what price I was willing to pay based on web delivery available. If I were to do it again. I'd replace all of them to be sure nothing is/will leak. I don't know and am hoping the manifold gasket wasn't necessary as I only went as deep as pulling the turbo. I tried to do the drain seals without pulling the turbo as I had read that it isn't necessary but found the turbo easy to remove. It would be easy to replace manifold gasket as you're already there.

oldsinner111 · #7 12-30-2009, 11:15 AM

I'm real skinny,I reached up from underneath car to get bolts to turbo.I used a little 3/8 stubby rachet.

jamesNB · #8 12-30-2009, 07:42 PM

Thanks for the insight everyone. I was finally able to remove the oil drain tube without removing the turbo. I came at it from under the car with a 2 inch extension to get the bolts off. Working the pipe out was a real pain also.
I also managed to remove the drain pipe from the air cleaner to the oil pan and replace that o-ring. I'm going to wait until Friday to try to reassemble everything. That may be harder than getting everything apart. I may still end up having to removing the turbo but right now it doesn't look like I'll have to. Thanks again.

Junkman · #9 12-30-2009, 09:25 PM

Quote:

Originally Posted by jamesNB

I'm going to wait until Friday to try to reassemble everything. That may be harder than getting everything apart. I may still end up having to removing the turbo but right now it doesn't look like I'll have to. Thanks again.

I ended up using 3 long 3/8 extensions to seat the tube.

pic: http://www.peachparts.com/shopforum/showthread.php?t=267412

pawoSD · #10 12-30-2009, 09:44 PM

Quote:

Originally Posted by Hit Man X

If you are pulling that, there is some sort of check valve in there that you should consider replacing.

There is no check valve on the turbo oil return pipe, just on the air cleaner return tube.

It is not hard to get those two 13mm bolts out that hold the upper pipe to the turbo, just just a 3/8" ratchet that has a flexible handle + a 6" extension + a universal joint + a 13mm socket. Then it is easy.

jamesNB · #11 12-31-2009, 07:37 PM

Well I've got the upper and lower drain tubes in place but I haven't connected it to the turbo. I'm sure I ordered the gasket along with the 0-rings and seal but I can't find it. So I'm stuck until I get the $1.25 gasket.
I hope this fixes the oil leaks. Over the past couple of years, I've replaced:
turbo drain seal and o-rings
air cleaner oil return o-rings
oil pan and gasket
front main seal
I think that only leaves the rear main seal and the upper oil pan/block gasket as sources of oil leaks. Neither of which I want to mess with. I'm hopeful, one day soon, I'll be able to say my 300SD doesn't leak oil.
Up next-- a valve adjustment and new brakes all the way around (and a brake fluid change of course, and change the air filter, oh and it's time for new fuel filters, and wiper blades, and tire rotation, and I really should change the rear differential oil, it never ends).

pawoSD · #12 01-01-2010, 01:00 AM

It should fix the leaks so long as everything is in good shape. I found that my major leak from the turbo tube was not the gasket so much as a few pin holes in the base of the pipe where it meets the pan!

I flipped the pipe so that portion is now at the top, and I did a smooth nice epoxy job to seal the pin holes. So far 0 leaks and it is clean and dry.

Dionysius · #13 01-01-2010, 08:11 PM

Quote:

Originally Posted by pawoSD

I flipped the pipe so that portion is now at the top, and I did a smooth nice epoxy job to seal the pin holes.

Are you referring to item # 94 ["Oil return pipe (upper part)"] in the diagram given by the original poster???

pawoSD · #14 01-01-2010, 08:41 PM

Quote:

Originally Posted by Dionysius

Are you referring to item # 94 ["Oil return pipe (upper part)"] in the diagram given by the original poster???

Yes, technically it is the lower portion though.

It works either way as it is identical at each end. Since I did a giant epoxy repair on the pin-holed end, it would not have fit inside the gasket at the pan, but does not interfere with the connection to the upper pipe.

whunter · #15 01-02-2010, 12:34 AM

Quote:

Originally Posted by jamesNB

I've got some oil leaking from the oil return pipes from the turbocharger on my 1979 300SD so I'm planning to replace the o-rings and the seal at the oil pan. I can't seem to get to the two bolt that attached the upper pipe to the turbocharger body. I can get a socket on them but I can't get any leverage to loosen them.
1. Do I have to remove the turbocharger to access the two bolts?
2. Is removing the turbo a big deal?
3. The manual mentions using "heat resistant nuts and bolt" to reattach the turbo to the exhaust. What are these? Stainless? Black Oxide?
4. Can I reuse the 30 year old nuts and bolts?
Thanks

Here is all the data you should need.

W126 OM617 1985 300SD turbo drain tube gasket & seals
http://www.peachparts.com/shopforum/showthread.php?t=113087

Exhaust leak between engine and Turbo OM617
http://www.peachparts.com/shopforum/showthread.php?t=176625

Have a great day.