C-6 Strange Leak

[J. W. Hall]

1968 F250 91K miles, 2WD C-6...

I'm sure it's just strange because I don't know what's going on. Here's the story:

I had the C-6 rebuilt a few months ago. It leaks like this:

After driving it, no leaks the first day the truck sits all day. Second day the truck sits, no leaks. Third day the truck sits there are a few spots of tranny fluid. Sometime around the third to fourth day, the transmission dumps a whole lot of fluid onto the driveway.

I took it back to the shop and told them that it was leaking. They kept it overnight and returned it saying they hand adjusted bands and tightened something. Once I let the truck sit as described above, it did the same thing.

This took a while to discover, since I usually drive the truck everyday, or every other day. It seems that if I drive it, there are no leaks for a day or two. It only leaks when I let it rest for several days in a row.

I plan on taking it back to the shop. But before I do, I'd like to get some input to compare to what the shop is telling me.

There are only so many seals from which to leak, right? Is the pressure keeping a seal sealed, and when the pressure drops, then the seal doesn't, and the trannt starts to leak? Does that make sense? Is there a seal that behaves this way? I'd be happy to give it a go myself if there is a seal that I should redo.

[RTG_RACING]

I have rebuilt a few C6 and C4 autos. Something in the build is wrong. Sounds like the shop needs to pull it and take a better look. You can't where the leaking is comming from? I might be able to give you an idea if you can give me a general idea of where the leak is.

[baby_gonzo]

My C6 does the same. I was told that the torque convertor is starting to drain back from sitting, and was told it was coming out of the gear selector seal. Mine isn't rebuilt though.

[Wes]

it happens to alot of auto trannies esp older c6's your fresh rebuilt should not thou.