Here we go again...Trans fluid dumping.

[eightbanger]

I have th400 and had a leak a while back where the fluid would dump after a drive which I tracked down to a small hole on top of my trans, but it did not happen all the time...so not knowing what I was doing I filled the small hole with bondo then posted on the board about it,(pics here)
http://67-72chevytrucks.com/vboard/s...d.php?t=296816 and found out that I should not have filled that hole as preasure would build up in the tranny. Also that there should be a small metal breather tube comming from the tranny where the hole is but it has been removed or broken off over time, anyway after unpicking the bondo no further probs until now. It has dumped big time through the dipstick sprayed the dizzy, fire wall and poured all over the exhaust...scared it was gona catch fire on the way home, smoke everywhere......so is it preasure related? and why would preasure build up? is it overheating? the fluid was vey hot when it was coming out, why would it overheat? have not been able to use my truck all week as soon as I drive a few hundred yards I can see the smoke trail behind me and the gears are not shifting smoothly now, there is little or no fluid left in there now.
I guess my main question is....can I find and fix the prob myself? (with the help of you guys) or is this a job for the pro's??

[too much stuff]

Hi, how are ya? First thing i would do is find out where it is coming out of. It sounds like it isn't breathing correctly. Hence the "breather" tube on top of the case. Make sure it is clear. A trans cooler will help with the temps some. As far as not shifting properly, it is probably low on fluid. Let us know what you find out. Eric

[eightbanger]

Hey Eric, definately dumping through the dipstick this tiime, but previously from that breather I suppose it could still be blocked from the bondo as I did really trowel it in there. But even so if I never had blocked it up it did dump from that hole before, so something is going on in there to make it spew fluid from any exit point it can find. I've missed driving my truck this week Eric have to walk past it on the drive and get into my **** box 95 BMW to go to work.

[too much stuff]

Is it coming out the top of the dipstick tube? or where the tube goes in by the pan? Dumb thought, but i had a hurst converter in my car that had a crack in it and that threw fluid everywhere. Also, if the front seal goes out that will dump alot of fluid that will get sprayed everywhere. Do you have steel lines going to the radiator?

[eightbanger]

Definately at the top of the tube as the dipstick was pushed out by the force and it had sprayed the top of the firewall and the dizzy in fluid I was sort of glad it was easy to find where it had come from as tracking these leaks down after they have covered everything in fluid can be hard. And yes to the steel cooling lines to the rad, do ya think I would be able to drop the tranny out myself?

[boogie67]

I had a 75 grand prix that blew fluid out the dipstick.It turned out that the trans cooler in the radiador had a hole in it and letting water mix with the fluid .

[Boog]

8B. If that is the case here you better be checking the trans fluid level to be sure it is not going up indicating coolant in the trans fluid. That water will steam the material right off the clutches in short order and you will be looking at a rebuild. Radiator coolant level drops and trans fluid level rises...that's bad.

[eightbanger]

Thanks for the suggestions guys. But just to update on this I got home from work early and decided to get the truck up on a couple of wheel ramps with a mind to removing the tranny myself and giving it a little overhaul in the evenings and weekends. So I put the ramps in place started her up dropped it into gear and...Nothing, not even the slightest bite from any of the gears, so something has gone badly wrong in there. Well I think I'll leave this one to the experts, I'm bowing out, found a guy that rebuilds these here in the UK and he has an Ebay store as well.
http://www.aldersautomotive.co.uk/

[Sinister]

Does the tranny have enough fluid in it?

[eightbanger]

Pretty much empty, it dumped about 3 times last week when it was still being used, really hope I haven't buggered something up driving it home.

[Sinister]

That's why it won't move. Put some fluid in it. Check the level with the engine running, after putting it into all the gears.

[too much stuff]

Add some fluid for sure if you are trying to move it. Even if you are down 2 quarts, that will be enough to make it not move.
I am still guessing the breather is plugged and that is where your problems are starting. If you add fluid, make sure you add the same as what is in there already. I run type F or FA in any new ones. Yours may be dexron.
Keep us posted. Eric

[eightbanger]

Way to go!!! thanks sinister & Eric you clever 67-72 truck owning dudes. This just illustrates how little I know, but since the gears are engaging now I have put it on the ramps and will have a look and see if I can remove the Tranny myself to save money....but I ain't gona work on it, it's going in to the shop.

[Sinister]

Glad it worked out for you.

[eightbanger]

Well since my last post I removed the Transmission and left it in for a freshen up, the guy said that "he found no real probs with it", he just tightened up the clutches all new seals and added a new breather tube that was missing from the housing.
So it went from this...


To this....


So the reason for my Trans fluid overheating & dumping passed to the Converter which was a TCI Sizzler 1700 stall, he did some checking and said that as it was quite old and was never really up to the job being mated to a 454 with a mild cam, he reckoned this was the prime suspect.
So I replaced it with a B&M Holeshot 2400 stall, added new Mini Starter, Flex Plate & Trans mount for good measure.


So far so good, no overheating fluid dumping issues. If it starts to show signs of this happening again i'll go for the added external Trans fluid cooler.

[LockDoc]

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Glad you got it sorted. I think it will drive like a new truck now....

LockDoc

[big_al_71]

I think you should still ad an external tranny cooler and play it safe...I have always added one to all my trucks..

[eightbanger]

Originally Posted by big_al_71

I think you should still ad an external tranny cooler and play it safe...I have always added one to all my trucks..

I hear ya Al, I will be keeping a close eye on it.

Originally Posted by LockDoc

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Glad you got it sorted. I think it will drive like a new truck now....

LockDoc

Thanks Leon..

[fine69]

I had this happen once. Turbo 400 also. Called my tranny guy. He said it was the front pump that was bad.

Took it out, had him rebuild it.

Never any problems after that.

[gcburdic]

Nigel...glad everything is okay!!!

[monte0185]

Glad everything worked out for ya. I know its pretty easy over here to find people who rebuild trannys and stuff I would have no idea where to start over there. I would imagine most people would say "You have a what?"

Only takes a few min to install an external cooler. If you running a stall its a good idea regardless. What I usually do is unhook the bottom line to the radiator connect a hose to it going to the external cooler then connect the other side of the cooler to the radiator. This way you have two coolers essentially.

Beat of luck.

[eightbanger]

Originally Posted by fine69

I had this happen once. Turbo 400 also. Called my tranny guy. He said it was the front pump that was bad.

Took it out, had him rebuild it.

Never any problems after that.

My guy never mentioned the pump in mine, hope he checked it.

Originally Posted by gcburdic

Nigel...glad everything is okay!!!

Cheers Geoff! It's just great having my Truck back on the road again...

Originally Posted by monte0185

Glad everything worked out for ya. I know its pretty easy over here to find people who rebuild trannys and stuff I would have no idea where to start over there. I would imagine most people would say "You have a what?"

Only takes a few min to install an external cooler. If you running a stall its a good idea regardless. What I usually do is unhook the bottom line to the radiator connect a hose to it going to the external cooler then connect the other side of the cooler to the radiator. This way you have two coolers essentially.

Beat of luck.

We have a very strong Classic American car association here in the UK, but even so it's not easy finding a specialist to do specific jobs. There is quite a nice looking Trans cooler out there, the Finned Aluminium dual pass ones that come in different lengths.

Thanks monte.

[Myself]

Hmmmmm "tightened the clutches"????? Sounds suspicious to me. I've rebuilt a TH350 but not a TH400. But, I'm pretty sure that's not possible.

[eightbanger]

Originally Posted by Myself

Hmmmmm "tightened the clutches"????? Sounds suspicious to me. I've rebuilt a TH350 but not a TH400. But, I'm pretty sure that's not possible.

Probaby my lack of knowedge on this kinda thing and I quoted him wrong, maybe it was "adjusted" excessive end float was mentioned to, but i'm foggy on wether that was the Trans or Converter he was talking about.

[too much stuff]

Glad to see you are up and going! How do you like the new stall?
Eric