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4L80-E draining fluid overnight

I'm stumped. I can't find the leak. I replaced the gasket...re-sealed the wiring harness connector. No fluid visible on the pan or around it.

The fluid is draining from the top and dripping onto the rear tranny support cross member, then drains down the crossmember to a hole and onto the street.

I ran the truck for about an hour and climbed under it...no signs of any leakage. Half hour later, still no signs of leakage. Thought I had it fixed.

Went out this morning and found a puddle under the truck. It is dripping pretty steadily now.

This is a 92 K2500 with 454 (7.4L) extended cab, long bed with 187,000 miles on the truck and 110,000 miles on the tranny. No slippage or any other reason to replace the tranny. I'm about to drive it into the dessert, strip the VIN and leave it for dead...but I wuv my truck.

Do these things have drain back valves? I can't find one.

Any help?

Nate

Reply to
Nate
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Nate:

Anyway you can git an articulated mirror (a mechanic's mirror) up on top of that trans and see wherethat fluid is pissing from. It almost sounds as though some kind of pressure has built up inside the sob and it's coming out the breather. Do this next shutdown-pull the dipstick out and see if it has any puddle under it the next morning. Hopefully no cracked case either.

Respectfully submitted,

Loren Knighton Woodland, CA.

Under the hood since 1964 Member TRNI IATN

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BACKNCARDR

Sorry guys. Based on my post, you're all on the right track. The same track I was following. But one minor detail was overlooked on my part...sometimes new parts CAN be bad right out of the box. The new pan seal was leaking. Gawd I feel stupid. Got a new pan gasket from the dealer (Freakin expensive seal I might add) that has the crush collars. Will install this weekend after all the tranny fluid leaks out to below the pan level so it won't be such a messy job...LOL

The seal has started to disintegrate in many spots. It looked fine the other night after a cruise. But it apparently failed in the rear, right above the motor mount (should it be called a tranny mount?) where it is hard to see. I assumed, since it was a new seal, the leak was coming from above. I always look like an mule (PC cleanup tool) when I assume. The oil then dripped off a lip of the seal, preventing it from getting the pan itself wet. Last night there were six spots where I can see the seal has broken...mostly near a bolt hole...and beginning to squeeze outward. 8 dollar gasket from NAPA (comes with a filter)...money thrown into the wind. I could take it back and bitch...but I think I'll just get on with my life. NAPA doesn't have a history of supplying bad parts so I won't blame them.

Thanks for the input and sorry for wasting your time.

Nate

Reply to
Nate

Nate,

Are you sure the new gasket was bad? Make sure that you torqued the pan bolts correctly and didn't strip one out. (Been there, done that!)

KB

Reply to
KB

I am sure the new gasket failed...but I can't say I'm sure it was bad. My torque wrench could be out of calibration. But I do know that I did not strip out any of the bolts. The gasket material is falling apart...you can see the pieces coming out from between the tranny body and the pan. I'm thinking that the permatex gasket sealer had a reaction with the rubber gasket material. The OEM gasket I picked up will not need any permatex. The rubber one probably didn't need it either...but I am notorious for overkill on seals.

Nate

Reply to
Nate

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