84 Auto trans leak

[1984C4]

Hi all. My 84 has been in the garage all winter and has been steadily leaking tranny fluid staticly, about a pint the last couple of months. Just pulling out the dipstick with a very cold engine the level is about 3 inches above the full hot line. Could this be because the tranny is overfilled? I checked it when I got the car a few thousand miles ago with a hot engine, idling and it was at the full mark. Could there be some internal check valve that that is stuck closed not letting the fluid drain into the pan after shutting down and this fluid is finding its way out the breather or dipstick tube from a bad O ring? The fluid is dripping from the transmission dust cover weep hole at the forward part of the tranny. The odd part is after the engine has been running a while I think it stops dripping. I plan on investigating further when it is warmer and I have more time but right now my job (USN) only allows me to get home once every 4-6 weeks for a few days. Just looking for some suggestions. I want to flush/fill the tranny and then change the filter but not if it will still leak afterwards. Thanks. Mike

 

[C4CRAZY787]

To be sure of a correct reading you need the transmission hot not just the engine, to do this take it out for a 20min drive then with the car level in park engine running check the fluid level.

Sounds like a pan gasket or like you say dip tube O-ring, generally a front seal will only leak during driving and a short time parked.
Good Luck, and Thank You for serving our great country

 

[1984C4]

C4Crazy, thanks for the reply. The pan does not appear to be the problem as I can see it all. I guess I meant to say I checked it properly with a hot tranny instead of engine with the car running, level surface, in park and it was normal. I guess I need to know if it is normal for a cold engine/tranny fluid level to be that high on the dip stick. I would think that it would be lower on the dipstick until running and hot. Again this reading I'm talking about is with the engine not running as I don't want to start it until spring unless I plan on driving it Could someone please pull their dipstick out of their cold non running, non leaking car and tell me how high the level is? Thanks for a wonderful web site. Lots of great people here. Mike

 

[C4CRAZY787]

Could someone please pull their dipstick out of their cold non running, non leaking car and tell me how high the level is?

On my 700r4(4L60) it reads about 1" higher than the full mark. Its been sitting for about 6hrs so its not stone cold.
It could very well be the front seal, mine started leaking after a night at the drag strip last Aug, it leaked off and on for about 2 months then just stopped. I took care of that with a new ft. seal when I installed the new converter.
If your Vette sets a lot this could be part of the problem. Funny things those seals. Hope this helps, Good Luck.

 

[1984C4]

Thanks again C4crazy. It will have to wait until May when I get home again and maybe get a few days to look at it.

 

[Bob Yates]

I had a leak like that on my 86 C4 and it was the front pump cover gasket. I took the fly wheel cover off to get at the pump plate and cleaned it with brake cleaner. The leak must have been at the bottom of the plate because I use a product call leak ender and sprayed it and let it set a day and it stop the leak. That was two months ago and it is still leak free. The funny thing is I thought all along it was the pan gasket and replaced it several times. To answer your cold reading problem as long as your tranny reads full when hot your ok. You'll always get a high reading when cold. Thats normal. Good Luck. Thanks for serving Our Country....

 

[Vettefan87]

My brother had a leak on his. It was the yoke off of the driveshaft. It was grooved from obessive torque or something like that.

 

[1984C4]

Thanks Bob and VetteFan87 I'll check those out when I get back home. I appreciate the "thanks for serving" comments. Just doing my part for this great nation. Others have given more God bless them.