Gasket sealer


Well Known Member
Supporting Member 8
Hi everyone. Just trying to gather up as many opinions as possible re. using a gasket sealer on a TH400 transmission pan. Yes? No? Just seal it to the pan? Both sides? Thanks as usual, Carmine.


Bob after you rebuild that rear end maybe it's time to rebuild that leaking transmission. :D
It's a powerglide thing. I put new seals and pan gasket and if you let it sit, it eventually spews fluid from every pore! I keep a large pan under it at all times! :D My 69 Chevelle w/powerglide does the same thing. (and I've heard many others with the same problem)


Well Known Member
Supporting Member 8
If this is a TH 400 the front pump O ring is a common leak.
The trick is to use a 700 R4 pump O ring.
Yes, a TH400 transmission. I'll have to take a look at a schematic and see where this pump "O" ring is located. If it requires removing the transmission, that will have to wait until I'm ready to change the torque converter, Carmine.


Well Known Member
I've never owned a powerglide that didn't puke on the floor after a period of no use!
You answered your own question why. If you start the car at least once a month, the fluid stays in the torque converter where it belongs. Let it sit for a long period of time, the torque converter drains back into the pan, and will overflow out the vents. My 1963 Chrysler did the same. It is really not leaking, it is just reminding you that it misses you.....