blandis

Looks like there is a crush type washer on the overload protection switch. Mine is leaking.

My question is can I snug it a bit and see if that helps or should I replace the crush washer. My concern is over torque and causing any further issues.

I also have a small pan gasket leak and will be getting parts from Roger to address that also. Figured while it is apart and replacing pan gasket, filter, etc. will take care of both.

Anything special I need to know before tackling this?

atb

Jim Bailey was a big fan of running a straight edge over the pan rails while you have it off the tranny. Use a hammer to make sure the pan bolt holes are flat. Good advice.

Tails

Ensure that you buy the updated pan gasket as Mercedes Benz modified the gasket. The last number in the part number for the old gasket is "10" and the modified pan gasket is "11".

It is imperative that you do not overtighten the pan bolts.

Tails 1990 928S4 Auto

soontobered84

Blandis,
Are you ever gonna update your avatar?

IMHO, use the stud kit when you replace you pan gasket.

Jerome Craig

Are you sure it's leaking from around the switch...and not from the connectors at the end of the switch? If your leak is around the crush washer you'll have to remove the OPS, and of course if it is leaking through the switch, the switch will need to be replaced. It’s an easy change, when you remove the switch the B1 band apply pin will/should be attached at the end of the OPS, secure the band pin with Vaseline on the end of the OPS when you reinstall. IIRC the band pin is "keyed" so it will only go back in one way.

Jerome

pdub

the original post on this thread was from my PO. The OPS is still leaking. Changed the o-ring #33 in below diagram. The post mentions a crush washer, but didn't see one involved. The pan gasket is still an issue and wondering if a new pan needs to be installed. Have changed the gasket but leak remains.

Open to ideas. While it may sound cheesy, is some good old fashion plumbers tape around the OPS an option to stop the leak?

pdub

Picture of leak...I know I am probably splitting hairs here, but it my OCD won't let it go...

dr bob

A new pan isn't expensive, and IMHO it's cheaper than ttwo tries with the hammer and straightedge trying to get a deformed one to seal. Most Critical that you use your best technique to get the bolts drawn up evenly, and use a good inch-pound torque wrench on the bolts. The sump bolts take a lot less torque than the two drain plugs, yet folks continue to twist on them while trying to solve a leak.

I put a smear of Teflon thread sealing past on the plug threads on those two drains.

The seal for the reservoir can be iffy. A spray of lubricant on the pan nozzle and the threaded part of te hreservoir fitting may help.

The brass inserts molded into the bottom of the reservoir have no tolerance for any thing more than 'just barely snug'. You want to keep it from falling off, no more.

Others will need to chime in on how to seal that overload switch.

Bill Ball

Under that switch is the B1 thrust valve and it has 2 o-rings. I'd pull that and replace its 2 o-rings. Also, the switch is torqued to 52 ft-lbs. I don't think Teflon tape will help as the threads are not sealing component.

pdub

Thanks Bill. I was going down that road next. Do you know about this supposed crush washer? I didn't see one in the PET? Nor was there one on my car??

dr bob

There's always the real possibility that the switch itself is passing fluid internally. If all the attempts at external sealing don't succeed, another switch might be the solution.

Don Carter

Paul,

Isn't the crush washer in the diagram you posted above, number 33?

Looks like we get some more practice installing that B1 thrust valve, what fun! Maybe if we replace your pan, we do the B1 work while the pan is off, and guide that plunger into it's hole from inside the tranny?

ammonman

If memory serves, part #33 from the diagram is an o-ring, not a crush washer. I don't think you can see the B1 band from below unless you remove the valve body and lower plate after dropping the pan. The pin on the B1 thrust valve is fairly well captured so you shouldn't have too much problem getting it in correctly.

Mike