[A//// Guy]

Scheides, were you just trying to get it to go back in to reinstall pads or were you trying to get the piston out for a rebuild?

If doing a rebuild, did you try blowing the piston out with compressed air? Put it in a vice and put a block of wood between the other side of the caliper so piston hits the wood as it pops out. This is the method ive always used for rebuilding a caliper. On my old motorcycle restore, I had to pump out the piston with a grease gun though. Much higher pressures there.