79 Automatic Transmission Leak Question???
Thread Starter
Heel & Toe
Joined: Dec 2006
Posts: 18
Likes: 0
From: Somerset KY
79 Automatic Transmission Leak Question???
I have a 79 L82 with 43.000 miles that I am getting ready to sell and have a minor transmission leak that I need to address first. The car drives and shifts great and after I drive the car and put it on the lift there are no leaks. The next morning several drops of fluid are under the car and another day later about a 12 inch diameter circle of fluid is under the car. The leak comes from the front of the transmission. I changed the pan gasket and shifter seal drove the car and its still there. I have now taken the bottom bell housing cover off and with a mirror and shop light it appears to have trans fluid on the bottom area of the front seal cover area. I have the gaskets and seals to relace but am concerned about the possibility of too much pressure or a ventilation blockage forcing the fluid out. I have the transmission almost out and plan on taking it the rest of the way out and beginning repairs this evening. Any suggestions or things I need to look for while I have it out. Thanks Bryan
Burning Brakes
Joined: May 2008
Posts: 1,116
Likes: 5
From: Middleburg Florida
Seals can get hard when they get old, and it sounds like that's the case with your front seal. Pull the trans, then the converter, and replace the $2.00 seal. Button it back up and your done. Trans cases are vented, it's a pretty big vent too, on the top of the case. It's unlikely that's blocked, but you can check it when you pull the trans to change the seal.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you are getting ready to sell it, leave it alone and tell the buyer that "there is a small oil leak near the front of the transmission". Since you really don't know what is leaking, that would be an honest statement. Let the buyer look it over and decide whether that is an issue or not.
If you dig into it and find exactly where the leak is located, it could open a big 'can of worms': What lengths will you take to fix that leak? What if it turns out to be a front seal and worn pump bushing? What will you then need to tell a potential buyer?
Just leave well enough alone or you will be making the sale that much more difficult.
If you dig into it and find exactly where the leak is located, it could open a big 'can of worms': What lengths will you take to fix that leak? What if it turns out to be a front seal and worn pump bushing? What will you then need to tell a potential buyer?
Just leave well enough alone or you will be making the sale that much more difficult.
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
If it leaks from the front pump area when sitting and not right after running, you'll likely find it to be the front pump o-ring and not the seal. The seal will leak when running, not sitting (fluid level lower than seal). Trans. fluid leaks are tricky to find sometimes. It's best to elevate the car, front & rear, wipe it all down and watch it. Fluid will travel along edges and drop off at places other than their origin. Dipstick tube and detent cable leaks along with pan gasket leaks have fooled more than a few into thinking the front pump o-ring and/or seal is the culprit. Pan gaskets should be of the cork & neoprene variety and put on dry against a flat pan surface and not be over-tightened. Just nice and snug and re-snugged a couple of heat cycles later.
Last edited by jimvette999; Feb 23, 2011 at 03:39 PM. Reason: correction
Intermediate
Joined: Feb 2011
Posts: 26
Likes: 0
From: Columbus Ohio
ive been told by a few guys w corvettes that your car will leak when sitting because the tranny fluid comes out of the torque converter and fills the pan up 2 much. not sure but thats what ive been told
