727 Transmission rebuild… help!

[Plymouth.Duster]

Hi, I’m new here so please excuse me if I’m posting this where I shouldn’t be.

A couple times now I’ve torn apart the stock 727 that we swapped into my Duster, new clutch packs O rings etc.

I’m having a problem when we bench test the front clutch, the air just hisses right through without applying the clutches at all. I replaced the piston seals, but that made no difference, and I know for a fact the seals are put in correctly.

What’s going on? Any help would be appreciated, thanks!

 

[oldkimmer]

How much air pressure r u using. Should be only about 30 lbs. king

 

[VOETOM]

I had a C4 once that had one of the lips seals that looked right was smaller. It did the same thing.
And look to be sure the check ball is not stuck open in the retainer.

 

[rbkt65]

assemble the front 2 drums and the front pump together without being in the case. you can air test it that way and, as oldkimmer says, no more the 30 psi. make sure all 3 parts are from the same trans and you are not mixing parts from other trans unless they are exactly the same.

 

[71Demon540]

I assume you have the stator sealing rings also in place