Gary's 2 442-S

My transmission losing transmission fluid from the filler tube where is going in the transmission. the rubber bushing was bad and I thought that was causing the problem. I changed it out and fluid was still coming from it. Now this apprears to only happen when the transmission has sat for a few hours or a day or so. I next bought a new Tube and bushing and the same thing happen againl I am not overfilling. It doesn't come out of there while I am filling however. It appears to me like there is pressure coming from some where and it is making the fluid come out. Any suggestion?

HolidayCoupe

maybe u have a kink in your trans lines?

jeffu231

If it is a 350 the kick down cable is right there also and it can leak and appear to be from the fill tube.

TripDeuces

The full level is even with the pan rail when hot and running. When you turn the engine off the fluid drains from the converter, valve body, etc. and will be higher after sitting. I would check that kick down cable like suggested. They are notorious for leaking on a TH350.

Lady72nRob71

I have been wondering about this - thanks for the info. Looks like no seal replacement until it is drained...

Gary's 2 442-S

i am going to check the kick down cable, but it is a new one also. The transmission is a 400 behind a 455 engine that is just recently had rebuilt. Right now the fluid level is low because looks like a lot drained out.

Lady72nRob71

The 400 has a kickdown switch, rather than the cable.
Is it possible you accidently damaged the tube seal upon installation?
I did that to an old motorcycle seal. Had to change it twice to fix it. Old seal looked fine though!

Rickman48

I use a dab of wheel bearing grease in the seal to trans and the tube to seal, to avoid pushing too hard and/or ripping or twisting the seal. [grommet?]
Works for me!

TripDeuces

TH400 originally came with a o-ring seal on the tube. The grease idea is good. That seal can snap, twist, etc in there so just be easy. You can also try different o-rings. That hole is .755-.758 in diameter so an o-ring with an outside diameter of .750 will work. You'll have to work out the thickness on your own but I would cheat toward the thin side so as not to twist/split it. On some of their dipsticks Lokar suggests using RTV just under the metal collar on the dipstick so it seals against the outside of the case as you drive it in. Just make sure you have the upper end of the tube supported.
For some reason I thought we were talking about a TH350 so disregard that kickdown cable talk

455man

I had that problem too. I had the top hat seal though. Bought a new seal and used a little rtv and have no problems.

Gary's 2 442-S

think i will try the rtv on it and see what that does. the old tube had the o ring seal on it and the new one doesn't

Toms cutlass

Resurrecting an old thread ... On a TH350 > replaced the standard O-ring on the dip stick tube with a #11 O-ring (3/4" x 9/16" x 3/32"), and to insure a good seal, I added an additional O-ring under the collar of the dip stick tube which seats into the lip of the transmission. The additional O-ring is size #40 (3/4" x 5/8" x 1/16"). I tightened the dip stick attachment bolt to the transmission case while holding the dip stick tube down firmly onto the transmission to make a tight seal at the top edge where the tube inserts into the transmission. No need for RTV. It looks like it was meant to have 2 O-rings since there is a small lip on the top edge of the trans where the tube inserts. Now I have two O-ring seals and it works great. No more dip stick tube leak.

Tom442

You might want to check the modulator O ring too that sits right below the fill tube on a Th400.