W126 OM617 1985 300SD turbo drain tube gasket & seals

[whunter]

A very good DIY is here
http://www.peachparts.com/shopforum/...d.php?t=112999

My contribution is the following pictures.
This job is not to bad.

[whunter]

More pictures 1.

[whunter]

More pictures 2.

[85drtysthbenz]

thanks for the pics....that should help me out a great deal...im not dreading this so much anymore

[Greg300sd]

Hi. Did this job on my 83 300SD....not too bad. I was quite befuddled after doing the job since I still had a leak and thought I must have skipped over something. Much to my surprise the lower portion of the oil return tube that I ordered came with a leak free of charge! ...So..if you are by chance replacing the lower tube check it by applying air pressure while under water for example. I had to remove the first "new" tube and buy a second one.

The other issue if not already mentioned is that you would want to drop the lower oil pan since you may have to dig out the grommet that sits on top of the lower oil pan. Bits of it will drop into the oil pan guaranteed if you have to use a pick to get it out. Good luck!!

[ascalise]

I replaced these on my 81 SD about a month ago and they leak just as bad as they did before. Any ideas?

[Pete Burton]

Originally Posted by ascalise

I replaced these on my 81 SD about a month ago and they leak just as bad as they did before. Any ideas?

I did this job on my SD back in 97 or so and it never sealed completely either. Did you drop the lower oil pan and inspect the grommet hole thoroughly to see if it was completely cleaned out? Do you have a fair amount of blowby on your engine? I think this was my problem. Also, I removed my tube without removing the pan, but it was such a bit** that I should have just taken the pan off, it would have been easier.

When I rebuilt my engine last year, it was much easier. All the parts were clean and easy to reach on that engine stand. I didn't even spill my beer I cleaned everything with rubbing alcohol first, and added a thin film of black RTV around the grommet. It's so leak free now I'm worried about rust.

[ascalise]

I did take off the pan to replace the gasket on that. Yes my engine does have quite a bit of blowby. At least more than i would think an engine should have. However, I've been told that this is normal on these engines.

[Pete Burton]

The blowby and normal diesel vibration drive oil to leak at that tube. New seals will help, but with the tube coated with draining oil and a lot of crankcase pressure, it's still gonna seep. How many miles on your engine, what type? You can add that info to your signature

[KCampbell]

I had a friend do this for me, along with starter replacement, at his shop yesterday.

The lower tube is sufficiently cheap (like $20 or so) that if you're paying a tech to do this job it is probably cheaper to trash the tube, but get it out quickly, rather than spend a long time trying to remove it intact.

As it happens my lower tube was corroded and leaking, in addition to a rock hard grommet, so it needed to be replaced anyway.

Kevin

[rwthomas1]

Having owned 3 other turbo vehicles the MB drain tube is the worst design I have seen yet. I did the seals when I had the head off my 617 but it still wasn't easy. I don't think the lower tube seated correctly as the grommet was very difficult to seat. It doesn't leak so I am not concerned. I just wonder why MB made such a simple piece so complex. All the other vehicles I have worked on just had a short section of rubber hose to connect the turbo drain to a boss or fitting on the block. Simple, effective, easy to service and cheap. RT

[Pete Burton]

Originally Posted by KCampbell

The lower tube is sufficiently cheap (like $20 or so) that if you're paying a tech to do this job it is probably cheaper to trash the tube, but get it out quickly, rather than spend a long time trying to remove it intact.

Kevin

wow, that's a really good idea. I'm such a cheap bas**** it's no wonder that never occurred to me.

[Pete Burton]

Originally Posted by rwthomas1

Having owned 3 other turbo vehicles the MB drain tube is the worst design I have seen yet. I did the seals when I had the head off my 617 but it still wasn't easy. I don't think the lower tube seated correctly as the grommet was very difficult to seat. It doesn't leak so I am not concerned. I just wonder why MB made such a simple piece so complex. All the other vehicles I have worked on just had a short section of rubber hose to connect the turbo drain to a boss or fitting on the block. Simple, effective, easy to service and cheap. RT

I'm guessing, but 1. To control interchangeability and reliability, they chose to have several different versions of upper oil pans rather than mess with that wonderful block. 2. Using thin wall steel tubing, they could achieve a significant thermal gradient as the oil leaves the turbine housing. 3. They knew that a rubber hose would get really hot/hard close to the turbine, and maybe they wanted metal all the way down, just to be sure.

Still, why didn't they make it one piece with 1 simple, hi-temp seal on the bottom? I'm certainly with you there.

Ok sir whunter...here is a question.
What are the part(s) names that we need to purchase to do this job?
I see a few different names/parts under fastlane and wanted to be sure.
Thanks

[whunter]

Originally Posted by Brandon314159

Ok sir whunter...here is a question.
What are the part(s) names that we need to purchase to do this job?
I see a few different names/parts under fastlane and wanted to be sure.
Thanks

Look under "Air Intake".
You need the following parts:
#1. Turbo Drain Gasket
#2. Turbo Drain Grommet
#3. Turbo Drain O-Ring

may need this, if tube is bad:
#4. Turbo Oil Return Tube