Put the rebuilt tranny in about 2 weeks ago. Added 8 quarts (deep pan) and put the rear up on jack stands to run it through the gears. Was still low a quart or two so I left it up on jack stands. Tonight I noticed about a pint or two has leaked out. Could this be from the converter? The lines are tight and the pan bolts are tight.
The converter drains back into the pan upon engine shutdown. That raises the fluid level in the pan, and fluid goes into the dipstick tube. That is why the fluid level on the dipstick is so high up on a cold, non running engine. Most likely the leak is where the tube goes into the case. Replace the O ring that seals it. On a clean transmission, you should be able to see this. This looks like it might be a better solution if you have a recurring problem leak, https://www.classictransmissionsolu...it-th350-th400-700r4-4l60-4l60e-transmission/
It ended up being a bad o'ring. As I was looking for one I came across one of these https://www.amazon.com/Dipstick-Filler-TH350-TH400-Transmission/dp/B0BX76NYVL. Has anyone used one instead of an o'ring?
The product descriptions seems to say it won't work for you if your tube was designed for an O-ring. Larry's got the answer above.
