Oil cooler and line replacement, '83 300D - PeachParts Mercedes-Benz Forum

#1 08-14-2003, 08:57 AM

My mechanic made a note on my last service sheet that the oil cooler and lines on my '83 300D were starting to show a little wear.

What do these do, where are they located? Is it a very involved job? How often does it come up?

In short...any thoughts would be appreciated.

Diesel 924 · #2 08-14-2003, 11:03 AM

In short, use the search feature. This subject has been thoroughly flogged. If you are not a solid 'medium' level do-it-yourselfer, don't attempt the hoses.

#3 08-14-2003, 01:12 PM

Don't buy new ones either. You or your tech can remove them and take them to a hydraulic hose shop. They can replace the rubber part of the line inexpensively and they will be as good as new.

As far as the cooler itself, I can't imagine one giving trouble unless it is physically damaged in a wreck.

Good luck,

dmorrison · #4 08-14-2003, 01:18 PM

The oil cooler is expensive. As larry said unless its damaged you don't need to replace it.
The lines, I had rebuilt for $37 here in Ft. Worth. New they are $150.

Dave

GregS · #5 08-14-2003, 01:46 PM

You SHOULD buy new, direct from the dealer, oil lines. I say this because I bought an aftermarket line from an online Mercedes parts shop and it started leaking within a couple days. The hose is composed of an outer protective layer, and an inner reinforced layer (wrapped in fabric). The outer protective layer literally split open, and the inner layer was leaking. For this part I would strongly get the OEM part. It was only $75 from American Service Center.

Here is a link on how to do this job yourself:

You CAN replace oil cooler line without removing the motor mount.

GregS
'84 300D, 176k
'90 300CE, 167k

dmorrison · #6 08-14-2003, 04:49 PM

Greg
I have to ask. Reviewing your method of R+R I noticed you bent the hose, rubber section, back until it touched the metal section to remove it. Is this were you had the leak occur??? Could the bending while re-installing cause the hose to weaken and leak? I'm not picking on you, I was just curious. I completely removed the engine mount arm to R+R my hoses. I did not have to bend the hoses in any way.
Now I will say that the hoses are not leaking, BUT I have not been driving the car since the R+R of the hoses. I will certainly post if the hoses do leak.

Dave

GregS · #7 08-14-2003, 09:02 PM

I can't imagine that bending a rubber high-pressure hose could cause it to leak, but anything is possible. These things are under what, 80+psi oil pressure, so I would hope they are pretty sturdy. I think I just got a defective one, but the consequences of having your engine oil all leak out are so great that I don't think its worth risking trying to find the cheap solution. I got the hose with the little Mercedes star on it and have driven with confidence ever since. You can also look at it this way - I installed the Mercedes hose the same way and it didn't leak!

GregS
'84300D, 176k
'90 300CE, 167k

coachgeo · #8 08-15-2003, 02:33 AM

my custom replacement hose was about $120 from Parker. Part of me wanted stock but part of me knew in my application the ones on it may not have been stock in the first place and could be longer. I would be REALLLLll weary of any high pressure hose that was made for $37 buks. That sounds scary..