Big time transmission fluid leak
 

Spent the last month sorting and fixing numerous oil leaks. Valve cover gaskets, Kleinholfer's half moon seals and banjo bolts and a new cam plug. No more oil puddles. So while I had a number of things removed I decided it might be a good idea to service the transmission. New vacuum hose, filter and gasket. Now the transmission leaks and there were no leaks before.

The new gasket is rubber and seamed thicker than the old one. I did some research and no gasket dressing was required. Should there have been? Some fluid seems to be from the front of the gasket but after drying it I stuffed a rag into the front of the transmission above the pan. That rag was soaked within a few hours. It may be leaking above but I can't find the source. Why would it leak now and not before if it isnt the gasket?

Another possibility is the transmission oil pick up tube and the new O ring I replaced. If this O ring was not properly installed would this cause a leak from somewhere above?

There also is a variance in fluid level. After I filled to specs(on a filter change not removal of trans) it showed way too full. I drained fluid and it leaked quite a bit and checked it again, still showed over full at cold. I let it warm up, ran it through the gears and checked level again. It was high but not too far over the full mark. I have let it sit for a week. There is now an approximately 20" diam spot of trans fluid on the floor. The fluid level shows way over full when cold. Level is above the flat part of dipstick and into the springy material.

Any suggestions on where to go from here? This seems way too messed up to be simply a bad gasket or bad gasket install.

I wonder if the trans is still over-filled? Has it stopped leaking?

If overfilled....and this might be worsened by drain-down from sitting unused for a few days.... the fluid backs up behind weak-ish seals and gaskets and then finds its way out! The seal for the dipstick tube being one of the more notorious examples.

Assuming the gross excess has already leaked out I'd check the fluid level again, cold, just to see if the level is roughly OK....not too high, not dangerously low. Then drive 10 miles. ATF needs to be HOT (not cold, not warm) to get an accurate reading.

Cheers
DD

When you service the tranny, not all the fluid comes out, as loads is in the cooler and torque converter. So you have probably wildly overfilled it if you put in the full amount for n empty trans.

If you pull the modulator by the dipstick tube any excess will tun out of the hole, and then you can siphon a bit out as well.

If you have the blue aftermarket gasket, which I have, mine leaked like a seive until you give it a VERY light dressing of gasket silicone.

Greg

To both Doug and Greg, I was thinking I may have over filled it. It does not appear to leak while running in neutral but leaks immediately after shut down. It is still measuring high after leaking out this past week. I will probably drain out from the vacuum til it stops and then give it another look. I started some body repairs and need to finish them before hitting the road.

I always use a bit of gasket dressing. A thin coat is all you need. Could you have overtighened the pan? Of if previous mech overtightened then the pan could be distorted. The reason it doesnt leak while running is because the oil level in pan drops while fluid is cycling thru tranny and cooler.

I agree with all teh above.

NOT related to what you have done, BUT, at the front of the transmission, RH side, UP above the vac modulator, sort of, (good Aussie descriotion here Grant), is a rubber grommet that the dipstick/fill tube pushes into. THEY LEAK, for no other reason than they can.

The rag pushed up above woke me up to that possibility.

Over fill is MOST likely teh culprit, they dont like it.

My HE runs a tad over, about 1/2ltr, when HOT and running checked, no leaks NOW, but that grommet did leak waaaay back.

Dressing on that gasket is always a good idea, as is checking that the gasket face of the trans pan is actually FLAT, bet its not. Never seen one flat as removed, as the Gorillas out there that overtighten those pan bolts in an attempt to stop leaks, distort that tin pan horribly.

Side note: I dont run a pan gasket on any of the older Jags, NO leaks, EVER. Same goes for camcovers etc, NO gaskets as such, just a bead of Hi-Temp RTV.