blandis

Have changed the gasket on the tranny pan twice in last few months. Had one that came with the car when I purchased it, never could get it to quit leaking.

Ordered one last week from Roger. Installed it and leaked in the front of pan. Drained and removed as I thought maybe it split and I had it pinched or something. Double checked everything, reinstalled gasket as it looked fine. Torqued 5 in/lbs at a time to 70 in/lbs.

Still have a leak off the passanger side tab that clips over the pan to hold gasket to pan. Seems to leak about a dime size puddle each time its shut off and sits.

Any secrets? I dont see it leaking from above gasket. Looks like its coming from under the gasket somehow. Overload protection switch has a bit of fluid where it mates to the case but dont think that is it as it is on the opposite side of transmission.

Thanks in advance for your help!

Landseer

O-ring beneath bowden cable is on passenger side.
Common point of leaking.

the flyin' scotsman

Did you service the gaskets and Oring of the reservoir when you did the transmission gasket?

The drain plugs of the tranny and TC have copper washers that should be changed also.

blandis

Transmission was serviced about month before I purchased it (10 months ago). Is not torque converter leaking. Pan had a leak when I purchased it. Changed the gasket with the one that came with the car...still leaked. That was 3 months ago.

Changed gasket again last weekend with a new gasket from Roger, still leaked and pulled it off yesterday and reinstalled. Is as good as its been since I have owned car. Dont see any leaking from above the pan...outside of the overload protection switch which is on drivers side.

Just wondering if this is a common area for a leak? Get another gasket and try again....third time may be a charm.

WallyP

Check the pan for warping or distortion from past over-torquing.

blandis

Wally best way to correct that if it is warped?

Mrmerlin

Chris may be onto something the bowden cable o ring will cause a leak.
Otherwise remove the pan and use a straight edge to check for pan flatness.
Tap it back into flush then install the gasket dry.
Also check the cooler line connections ,
any that are wet means the both of the lines,
if they are original should be replaced with new flex portions up to the cats.

Tails

Ensure that you have the latest modified pan gasket, It is Mercedes Benz part and the last two digits of the part number ends in "11".

Tails 1990 928S4 Auto

Bill51sdr

+2 When I first got my current car I had an annoying, persistent leak on the passenger side of the pan. The o-ring for the Bowden cable was not there. I put one in, leak solved.

Landseer

Best way I've found to change that O-ring is with pan off.
That way you can manipulate the simple spring lever to which the cable end attaches, making disconnection and reconnection of the cable much simpler, enabling access to replace the O-ring.

Mike LaBranche

Yeah, my first thought is bent pan. Somewhere along the line, some do-gooder put some torque on those bolts and flexed the pan, which now has a memory. R and R a few times would improve it, but I'll bet it's a bit crooked... not the install, the part.

Tom928

I have been chasing a leak since I replaced the transmission.
The leak is on the passenger side. It usually leaks when I shut off the car. Pan gasket replaced twice.
Pan checked for warpage - none found (by me or the trans shop).
Yesterday, I replaced the bowden cable o-ring (the old one was hard) and the o-ring for the reservoir tube.
I put new ATF in and ran the car for about an hour to let it warm up and get the level right.

Got up this morning and checked the drip pan - it's dry!!
No wet area's around the gasket and no drips hanging from the pan.
I need to drive it and see what happens, but the rain here in the PNW has been pretty heavy for the last few days.

Cheers,

Leon Speed

Anyone happen to have a picture of the o-ring on the bowden cable?

Bill51sdr

Leon Speed

I figured some wise guy was going to do that