Transmission fluid leak

Hello All!
New to the forum, so I hope this is the right place to ask this question.

I have a 1970 Buick GS 455 convertible that I restored a few years ago, first project ever like that. It is all stock. I have noticed that when driving the car, I have no leaks, but if the car sits for 2 weeks, it will leak up to 2-3 quarts of transmission fluid. It doesn't appear to be coming from the trans pan, nor the trans fill tube. Any ideas? I have been having to put a drain pan under it when storing for the winter, but would like to not have to. Thanks for any insight

 

Is it coming out of yoke area?
Just fixed this on a customers car.

 

Pull the inspection cover and look at the transmission bell housing. Sounds like a front pump seal. They will hold fluid as long as you drive but once you stop, the seal will shrink up and dump fluid. I had this issue for years before I finally got it fixed.

 

If it's coming from the front, it's most likely the pump seal as Ryan said.

 

3x on pump seal. Lot of work to fix since you have to pull the tranny.

 

Check your anti freeze. Is it ugly? The tanks of the radiator can leak.

 

The converter is draining back over time and filling the transmission. It's puking out a seal that isn't normally submerged.. there are quite a few places it can leak when this happens. You'll have to crawl under and see what is leaking.

 

Thank you all for your quick responses. It is definitely coming out the front of the tranny, so the pump seal seems to be my focus next! Thank you all!

 

check the shift shaft. There is a seal there that if it leaks it will run to the front for the pan.

 

Since u have to replace the pump seal u might as well replace all the seals & gaskets.