Sudden Transmnission Leak - Any Ideas Why???

GC · Veteran Member

Sudden Transmnission Leak - Any Ideas Why???

67rag396 · Poncho Master!

My guess is that the elusive transmission gremlins have invaded your shop. They delight in messing with peoples' minds.

I don't know the real answer LOL.

Ghost Post · Poncho Master!

Just a thought but on the Ford, I think some have a drain plug in the converter that could piss itself if loose or other problems..
Also if it has the drain plug and someone didn't line the plug up w/ the relief hole in the flex plate, it could have taken time of being pressed against the plate to leak?.
Without adding juice, what's the level at?.
And when you start the truck and pop it into gear does it slip right away like the converter is empty?.
And is it finished leaking the way it sits now but if you do the reverse/drive thing at idle to suck fluid into the converter, does it piss itself again?.

Good luck!.

GC · Veteran Member

Ghost Post wrote:

Just a thought but on the Ford, I think some have a drain plug in the converter that could piss itself if loose or other problems..
Also if it has the drain plug and someone didn't line the plug up w/ the relief hole in the flex plate, it could have taken time of being pressed against the plate to leak?.
Without adding juice, what's the level at?.
And when you start the truck and pop it into gear does it slip right away like the converter is empty?.
And is it finished leaking the way it sits now but if you do the reverse/drive thing at idle to suck fluid into the converter, does it piss itself again?.

Good luck!.

Thanks for the input. I have never seen a drain plug on the converter for C6 transmissions in that era of truck so I am thinking that the problem is not related to that. Besides, our Buick wagon with a Turbo 350 did pretty much exactly the same thing. I'll get under the truck today and see if I can determine for sure where the oil is coming from - I know that it is the front of the transmission but I'll see what I can see. I sure do hope that I don't have to pull that transmission and replace the front seal. *sighs* I hate transmission work.

-- Edited by GC on Thursday 11th of June 2009 04:09:23 PM

Ghost Post · Poncho Master!

I'm no Ford guy so don't know if those years had the drain or not but just thought it worth checking..

What's the situation w/ the level and if the converter seems empty or not?.

427carl · A Poncho Legend!

I had a 69 Nova, that I had put a 400 turbo in It would puke out "gallons" of fluid, while it was parked for winter.. I would fill it up, and it would not drip a drop all summer ?????

Elroy · Poncho Master!

I used to sell a GM product called ATC way back in the GM days. This product was a seal swell and transmission rejouvenator. A lot of the problems with automatics is the heat and clutch packs really take the toll on the fluids. They break down and then the seals all harden and you have problems everywhere. Remember to change out the fluid every now and then and if not add some of the ATC if its still available ?? Even the dipstick tube has a seal on it and a lot of fluid can puke out of that little seal leaking as was the problem similar on my sons El Camino. There is a nice tube changeup with a lip seal that makes a huge difference there too.

GC · Veteran Member

Elroy, So is the culpret the front input shaft seal then?? If so, then it dounds like it needs to be changed which means pulling the automatic. Again, I say - bleh

to that job. *sighs* I am thinking that if this is indeed the case then it is because the torque converter has drained back into the transmission body... aww YUK! disbelief

Please tell me I am wrong... *sighs*

2drpost · Uber Guru

atc worked ok, brake fluid will do the same.

had a cad deville a few years ago, front pump seal leak, won't leak all the time though.
added a 1/2 bottle of brk fluid, never leaked again.

73SC · A Poncho Legend!

69 belair wrote:
had a cad deville a few years ago,

Hmmm, why is this the first I heard of this confuse

GC · Veteran Member

I haven't heard of using brake fluid before but it stands to reason that it will soften and swell the seals up. confuse

The thing that I don't understand is why the transmission didn't leak for a number of days and then suddenly the fluid puked out overnight. Usually a seal will leak and grow progressively worse over time where as this happened literally overnight on not one but on two vehicles. The Buick wagon had a slow leak and we put a quart of Lucus Transmission additive in and the leak stopped right away - until we parked it. Then, like the Super Cab, there was no leakage for days and then again, literally in a very short few hours, there was transmission oil all over the cement pad under the car - just like the Ford. I hate automatic transmissions - leaking, dripping, drooling, slobbering things that they are. evileye

87 player bird · Poncho Master!

My thought but if you let it sit for to long, the seals dry up and then when you run it, they blow.

gparis7 · Canadian Poncho Superstar!

Agree. If it's been laid up for a while it's probably the front seal. While my Pontoac was in the shop for body & paint, it started to leak badly. I had to pull the trans as soon as it came home, to replace the seal on the front input shaft. Not a drop since.

GC · Veteran Member

Well, I just talked to a local man here who is one of thebest mechanics in the area. He's hard to get in touch with but I did manage to talk to him this evening. He says it's most likely the torque converter seal.

Apparently when an engine and transmission sit for too long, the seal dries out and then it can tear when the engine is started. It still doesn't explain why it took two weeks for the fluid to suddenly decide to pour out - maybe some things are just better off not thought about. He said that an agent to cause the seals to swell is only a temporary fix so I guess I'll be pulling a C6 in the not too distant future. bleh

He suggested that with some things, it is best to just bite the bullet and fix it properly. I tend to agree. Thanks for the input guys... I really appreciate it. smile

gparis7 · Canadian Poncho Superstar!

That's the one.

59poncho · Poncho Master!

I was going with the Gremlins idea but whatever that "mechanic" says i guess is a good idea too!!! LOL

67BBSD · Canadian Poncho Superstar!

'O' ring at the bottom of the dipstick tube ?

4SPEED427 · A Poncho Legend!

I have seen this a few times and my own experience has been it's the filler tube seal. You should be able to see on the Buick at least if that's what it is by looking under with a trouble light. It should have run down the side of the case and over the lip the pan sits against. Not sure if the Fords do it but I've had it and so have a few others I know who store cars. I am told it's because the torque converter drains down slowly when parked for extended periods and the level gets higher than normal in the pan.

Not to say it can't be the converter seal but I've normally seen them leak out only when the trans gets hot, such as when pulling a trailer or working a trans hard while stuck.

Elroy · Poncho Master!

I havent seen a torn seal yet but they get hard and dryout. The front pump outer seal goes too, but I would really check the dipstick tube seal and the kickdown cable seal and the connectors for the cooler. All this stuff can leak and you can change the tranny out and it still leaks. The dipstick tube can leak and still run into the underpan too. So take some rags, clean it up good and run it and check for leaks closely with the underpan off . Only then can you tell if its the front seal . For units that are sitting, run em hard and get it good and warm and it might stop leaking for a while. Just sitting is the toughest on seals Find some conditioner, its probably solvent as that stuff swells seals quicker than you know what.

GC · Veteran Member

I'll be more than happy to crawl under the truck in the morning and check out the filler tube - I REALLY hope thatyou guys are right! Same with the wagon - I'll lift the front and get under there and check it out. I'll post what I find. Thanks again and any other ideas are more then welcome.. Gary

GC · Veteran Member

Well ladies and gentlemen, - and men maybe - it appears that the result are in and the leak is caused by...........*drum roll* ...... the dip stick tube seal! biggrin

That's the good news. blankstare

The bad news is that it looks like I will have to either remove the exhaust or pull the transmission to get at it. cry

I can't see up in there and I can barely get my index finger in totouch the bottom of the tube but the leakage is from that front corner of the tansmission body and not from the front seal as I had expected. I'll have to get back under there and really do some poking around but either way, it's not promising to be as easy as one would think or hope for. *sighs* hmm

Having said that, I really do appreciate the input and the time that everyone took to share your thoughts. Thank you. smile

Elroy · Poncho Master!

Don't give up too quick on getting that tube outathere. They are all very tight but you can usually change them without pulling much. If its really tight try jacking the tranny up and take out the mount thus lowering the back of it a bit-- may have to pull the driveshaft but maybe not ?? You might have to raise it rather than lower it too. You can sometimes pull the motor mount thru bolt and move that end around a bit too. If you had a GM,THere is a tube available with a lip seal... seems to me its pn 1400 something 0003 ?? Carl 2 might know it and a lip seal change up and it might fit a C6, or maybe Ford has one similar??. Try looking up a TH350 tube outa a 1980 gmc and you can cut the end off and braze it onto the rest of your existing tube if it doesnt fit, and that is a much better seal than you will ever get with an O-ring. I can get the PN if you need. I did this on the camino and it fit , just had to lopp the top end off cause is was long & i threw that chrome piece of SHHHt tube over the shoulder !

-- Edited by Elroy on Friday 12th of June 2009 03:28:21 PM

gparis7 · Canadian Poncho Superstar!

That's actually good news. Heck of a lot easier to fix than a front seal.