Technical Odd Trans Leak?

Have a th350 that has all new seals. The converter/ input seal leaks but only when I turn the engine off. Wont sweat a drop otherwise.. Anyone run in to this before?

 

As in turn it off and it immediately starts leaking, or shut it off and after a while it leaks?
The former I'd guess is the seal not having pressure behind, but wait for a GM guy to answer that.
The latter might be the converter draining down, which raises the fluid level in the case.

Is it only after it's fully warm? Perhaps a vent issue where heat expands things and pressure builds.

You might want to edit out the vehicle, it's Post-HAMB and the trans diagnosis doesn't care.

 

Thank you, it leaks immediately after shutting off for a few seconds then stops. The trans fluid looks milky, so I will be doing a flush on it see if that helps. Wondering if the moisture is building excess pressure just not overly certain how the trans work

 

During the flush, pressurize the lines and cooler. Make sure of no leaks and if it's part of the radiator, see if you get bubbles in the coolant.

 

How sure are you about where exactly it's leaking?

 

I have since eliminated the radiator cooler and gone to a external cooler. 100% sure its coming from input seal used a scope camera and verified dry above input seal.

 

It seems like extremely odd to me that it does not leak while running/ driving no matter how hard im leaning on it. Almost like there is a relief of pressure when shut down that makes it leak

 

This is not the norm for a vent tube being plugged, but you might check it just in case.

 

Is the vent open? look on top of the case, driver side, just behind the bellhousing bulge.

 

Yes vent tube is clear.