727 Rebuild Blues

It's a BB 727. My first build. I assembled the trans & have tried to air check it but no luck. Front pack bleeds down as quick as I put air to it. Somethings amiss.

Specs:

1. 1971 BB core - purchased as a supposed running core but when apart it had some water inside & needed alot of cleaning.

2. Changed all sealing rings, thrust washers & bushings. None were really out of spec. Added 5 thin clutches to the factory 4 clutch front drum.

3. Both lips face down on the front pack. Replaced them twice now.

4. Check ball moves freely in the drum

5. Replaced the pump with a rebuilt unit just in case.

6. Tried to prime the air port with some ATF but no change. Could here the fluid pushing out from the air now.



I know there were some changes at the 70-71 model year. Are there any sealing rings, etc that could be screwing me up here. Maybe this has some factory 70 pcs inside. I'm stumped & really want to get this off my bench so I can get to some other work done.



Thanks,

Jason