I still cant get my front power disc brakes to work..Still hard pedal..I used a used prp valve ..is there a way to check these?

Do you have rear disc also, if yes you can gut the valve turning it into a manifold.

Originally posted by 540cutlaSS:
Do you have rear disc also, if yes you can gut the valve turning it into a manifold. No just the front is disc the rear is drum

Do you have good fluid flow to the front calipers? Did you bleed all the air out? If you got good pressure to the calipers I'm guessing the problem isn't the valve.
Do the calipers slide properly on the slide bolts?
Also 71 to 75 prop valves are still available new if you want one.
AC delco combination valve part# 172-1350
or
GM # 1257177 71 to 75 chevrolet.