TF 727 Clutch Air Testing

Had to pull my trans apart after losing an o-ring on the rear clutch. Replaced the o-rings on both clutch packs, set the clearances for the plates and air tested them. The rear clutch engaged fine with about 30 psi of air, however the front clutch didn't really move. There is hardly any air leaking and what does is around the shaft (metal o-rings), cranked the air up to about 80 psi and same thing. I'm running 15 springs so wondering if the air just isn't enough to move the piston?