Re: Failed to pass air check.

Remove the pistons, remove the seals from the pistons and drums.

Install each seal separately and test the fit in the drum.

If there is one that fits too loosely replace it.

There must be some resistance when test fitting each seal.

Remove the metal, I hope, rings from the stator support and test fit each one in the drums.

For replacement seals you will probably have to go to a transmission shop and root through their saved box of goodies.

Installing the transmission at this point would be futile.
If the drums won't apply with air they sure won't apply with hydraulic pressure.