1985 300TD SLS leaking MOTOR oil??? - PeachParts Mercedes-Benz Forum

cestes · #1 10-28-2010, 10:43 PM

Hi,

I'll try to keep this story short:

I picked up an 85 300TD wagon two years ago. I was the second owner and it had 125k miles on it; the first owner took better of this car than his children.

I bought it with the intent of converting it to WVO (I know that makes a lot of queasy!).

I started the conversion but never finished... part of that process was to relocate the SLS reservoir. I actually substited a smaller reservoir and put it on the right side, behind the headlight. I basically put on longer hoses to meet up with the hard-lines, which I never touched.

I don't drive the car that much... maybe once a month for 25-50 miles.

My daily driver is down (waiting on parts) so I drove this one the last few days. Yesterday, it was raining, and I noticed a little oil slick coming out from under it... this is nothing new or remarkable in my driveway, so I didn't think much of it. Today, I noticed a little puddle when I came out of the office to go home. Upon inspection, it appears that the reservoir is overflowing, and not with it's usual, light colored hydraulic fluid. It looks like MOTOR OIL! Could the pump have failed somehow and be allowing motor oil into the SLS system? It's black! The only other thing I could imagine is that some long-dormant pocket of fluid somewhere in the back became unclogged and released some dirty, nasty stuff. But it looks a lot like motor oil, and the reservoir is full, as if it's drawing oil from the engine's lubrication system into the SLS.

Does this sound like a seal, or is the whole pump gone?

Thanks for any input!

vstech · #2 10-28-2010, 11:06 PM

common failure. oil seal o-rings need rebuilding.
one of the members have a kit i think, or click on the buy parts link and see if one is for sale.
you could call roy also and ask him...

tarnbarn · #3 10-29-2010, 04:14 AM

Hi,
Did this yesterday.
You need an allen key (6mm?) and two seals: 0049970147 is the oil seal round the shaft and 0109974345 is the ring seal for the 2 halves of the pump.
I decided to remove my radiator to make sure to get the allen bolts out without messing up the heads. Otherwise it takes 10 minutes to change the seals, but longer to clean all the sump oil out of the lines!!
You should probably also get the filter 0021845501.
I'm buying in euros at an MB dealer and the 3 parts cost under 20€.
Enjoy
giles

layback40 · #4 10-29-2010, 08:05 AM

I predict failed air cells in your future !! Sorry to be the prophet of doom

but unless you flush all the engine oil out properly, they will fail.

cestes · #5 10-29-2010, 11:57 AM

Thanks for the info... I found a rebuild kit and placed the order this morning...

How do I flush all the motor oil out? Just fill, circulate, and drain a few times until it looks normal?

Thanks again!

vstech · #6 10-29-2010, 12:16 PM

sort of.
you need to empty the reservoir, set the return line in a 5 gallon bucket, and fill the reservoir with fluid. (I used ISO 46 hydraulic fluid. NOT AW!) keep the reservoir full with the engine running until clear fluid is running out the return. then the rear valve needs to cycle through the up and down positions. you need to have the car up on ramps, disconnect the actuator from the rod, and carefully put the actuator in the highest position, then the lowest position. then back to neutral, while keeping the reservoir full of clean fluid.