egertge

well, it took me a couple days to get the tranny out, then a long time to replace the seal and get it back in, and now that it is in, it leaks in more places that it did when i took it out in the first place. it leaks around the kick down cable or whatever, somewhere in the back, and still in the front by the converter. what am i doing wrong to make it do this? is it supposed to leak a little when you fill it back up? i really dont think so means how it never did when i was replacing my pan seal. any suggestions? should i take it back out, or see if it stops leaking. i dont know why it would stop though.

rollavette71

Did you notice a worn groove in the surface that the TC seal rides on? If that groove is too deep, then fluid could leak by it.

Also, did you keep everything very clean? Seals hate any kind of contamination... the high rotational speeds will grind up the rubber in the seal and allow leakage.

And don't feel bad - most or all of us fight these fluid leak battles. It takes practice, experience, and often luck to stop leaks.

Good luck,

Hank :cheers:

egertge

i didnt see any grooves when i looked at it, but why would the other leaks occur? i unbolted that plastic piece where that cable goes in, then bolted it back up, but i didnt touch anything in the back. did i overfill it? do i need to fill a little, run it through the gears while its not moving, then fill it all the way? im not sure why these other places started leaking. the car didnt move since i put it back in, it was still on jackstands when i put the fluid in, so movement wasnt an issue.


[Modified by egertge, 6:42 PM 8/15/2003]

egertge

atf came out of the speedometer cable when i took it off this time. thats never happened before, does this mean it was too full? do i need to turn the torque converter in the transmission a couple times to get that seal to seal?


[Modified by egertge, 6:48 PM 8/15/2003]

vettes1st

Have you run the engine to circulate the fluid into the torque converter? It can come out the vent if over full and other places too.

egertge

i havent ran the engine yet. i tightened up where that throttle kick down cable goes it, it was a litle loose, hopefully that takes care of that. now im gonna take the exhaust off and see where it is coming out the back. i really dont want to drop the tranny again. after running a while, will that seal seal better? thanks for the info.

rollavette71

How much fluid have you put in so far? Did you drain the TC when you replaced the seal? Sounds to me like you very well may have too much fluid in it.

I would start your engine and check the fluid level right away, and then a few more times quickly while the fluid level stablizes. If the tranny is too full, then shut the engine down soon and drain some fluid.

Hank

egertge

i put in 5 or 6 quarts. probably too much. i drained it all when it started to leak. would it leak by the front seal if there was too much in it though? i put in 3 quarts after i drained it again and there are no leaks so far. tomorrow i will take it off the jackstands and start it up. then add more and let the tc fill up. hopefully there will be no leaking this time. how much should it take if the tc was half full and the pan had whatever didnt drain out the drain plug? thanks for the help.

Brettmc

Keep pluggin away at it...you'll get it stopped up soon.

Brett :thumbs:

Chevyguy

The trans and convertor will hold 22 pints empty. Take it off the jack stands, start it up and shift through PND etc, then check the dipstick. Can't help on that front seal still leaking, unless it wasn't installed correctly. Same thing happened to mine, started leakin again after 20 min driving. :smash:

egertge

well, went out to the garage this morning and there is a puddle under my car again. i think it is the front seal. will these seal over time, or should they seal right away? if giving it a little time might do the trick, i think i might just lower it and drive it. what do you guys think?

rollavette71

I'm no auto tranny expert, but I have replaced a tranny on a Grand Am... and a number of other manual trannys - so I have a little experience. If my understanding is correct, your front seal does not have much, if any, fluid pressure on it when running. It simply prevents oil "weepage" from leaking by the TC. So, if your tranny was overfilled, then perhaps the seal was "flooded," thus explaining the front leak.

I would make sure you have the proper amount of fluid in the tranny. Then run it for a half hour or so and see what the leak situation is. Even if the leaks are stopped by getting the proper amount of fluid in, you may still have some "runoff" from the previous leakage - so be sure to give it enough time to make sure you know what is leftover oil vs. a continuing leak.

Keep at it and good luck!

Hank

egertge

after taking a close look, it doesnt appear that the fluid is coming from the front seal. it looks more like it is coming from somewhere below that, like on the pump assembly possibly. are these known to leak over time? i cleaned up all around where the fluid is, and put a rolled up paper towel inside, hopefully i will be able to tell where the fluid is coming from by where the paper towel soaks it up.


if i only put 3 quarts in and havent ran the engine, would there be enough fluid to even be up by the front seal? i wouldnt think so, but maybe there is.

if i had to drop the transmission again, could i fill it up while it is out to check for leaks?


[Modified by egertge, 9:29 AM 8/16/2003]

egertge

well, i think i have determined that it is the pump assembly gasket. i took it off and put some fluid in it, and that is where it is leaking. i went from thinking it was the pan gasket, to the front seal, and now im perty sure it is the pump assembly gasket because i actually watched it start to leak. how do i change that gasket? if i unbolt that thing, is everything inside the transmission gonna fall apart, or will it just come out without messing with anything else?

arrio76

Most times when you stab the TC back onto the trans a small amount of fluid will pour out of the TC befor it stabbed all the way onto the transmission. This residual fluid may be part of what you are seeing.

Also you need to double check the cooling line fitting at the trans, Kickdown cable (plastic fitting), and the dipdtick tube to be absolutely certain that these are dry. The kickdown cable fitting has an O-ring or small boot/sleeve to seal it from leaking. It may not be up to the task and may need to be replaced. The same thing for the dipstick tube.

The 3 quarts you put in are only setting in the pan untill the engine is started. 10 to 20 seconds after you start the car, all of it will be pumped into the TC.

You will then need to add 2 to 6+ quarts, depending on how empty/full the TC was.

Another posibility if the fluid is definatly coming from the front area, and not from the seal, is that the pump assy itself is leaking. There is a gasket, outer large O-ring and pump bolts seals. This not as common as the leaking front seal, but It does happen. This means that the trans has be dropped again and the pump removed. Most trans shops should stock the gaskets and O-rings.

I don't think you can check for leaks while the trans is out. Too many connections. and you can't verify the front seal without the trans pump working.

The seals should seal right away and not take time to seal up. If it leaks right after intall, it will continue to leak.

As mentioned above, If the TC has even the stightest groove where the seal rides, it may leak past the seal. New TC required for this fix.

If the front pump bushing is excesivly worn it could allow the TC to move around too much to for the front seal work. The pump bushing is what the TC is supported on just behind the front seal. If the bushing is worn, the pump assy needs to be examined to ensure that the pump and gears have not also been damaged.

arrio76

To pull the front pump and not disturb anything else in the trans, you should stand the trans on end, on the tailshaft housing. You could also put a couple large screwdivers through the bellhousing bolt holes and hook the scewdivers over a sturdy edge, positioning the trans in a virticle position. Fluid will drain out, so be sure to put a container under the trans tailshaft when you do this.
To pull the pump out, after the bolts have been removed, you should be able to use a clamp or large pliers/visegrip on the outer splined section. It will be difficult to pull out, but since the gasket is leaking it should be easier than usual to pull loose. There is a special puller for this but you are likely not going to find one easily.

egertge

when the trans was on the car last night, filled, it did not leak anywhere but in the front, so i took the trans off again and filled it to see if the fluid was coming from the pump. it is, on the bottom, so i am going to get a new gasket for that. hopefully that will do it. one of my cooling line fittings is leaking. not on the trans, but a little bit away from it where two hardlines connect. how do i fix that? where are the seals for the bolts? are they those flat washer looking things?

Smokehouse69

I've been reading your posts and I feel your pain. :D My TH400 used to leak at every possible place. Here is a list of places that the tranny can leak from.
1. Front Seal
2. Front Pump Housing (o-ring)
3. Fill tube oring (if your fill tube is out of round the oring won't stop it from leaking.
4. Shift shaft (small seal, if the shaft is grooved it will still leak. Replace the shaft.)
5. Governor cover (gasket)
6. Speedometer cable (o-ring)
7. Read seal
8. Tail housing (gasket)
9. Cooling lines
10. Kickdown solenoid (o-ring)
11. Tranny pan gasket
And finally the case itself, that's right the Chasis Service manual lists porosity of the aluminum case as a problem. The fluid can leak right out through the case itself. The service manual suggest cleaning the case outer surface and then sealing it with epoxy to cure porosity.
I replaced all of the seals, all the o-rings and all the gaskets on my TH400, I also replaced the shift shaft, kick down solenoid and fill tube. I got the replacement parts from http://www.bulkpart.com
After replacing these things, I have gotten the leaks down to almost nothing, but it still leaks. The only thing I can think is happening is that I must be leaking through the case. So far it hasn't leaked enough to drip but the case that was clean on install now has a small amount of ATF on it. I can't see where it is coming from, but it is still there.
Good Luck!

arrio76

The hardline connectors (splices) are usually just a metal/brass fitting. No gasket, usually just snugging them up seals them up pretty good. If retightning the fitting doesn't do it, they can be had at your local auto supply store for a buck or two.