My dad and I bled the front brakes while I was waiting for the paint to dry on my rear calipers. I did not take the rears completely off, just off the rotors and taped them off. Well, since it was off the rotor, the piston is now clamped down from all the braking while bleeding the fronts. The two pads are stuck together, and I can't get the piston to retract. How do I fix this? I have tried everything, and it won't move. Anyone?

 

Your going to have to remove the pads. Crack the bleed screws loose on the rear calipers. That should release the line pressure allowing you to pry the pads out.

To retract the rear caliper pistons, you have to "screw" them in. The pistons are threaded, and must be threaded back into the caliper. A large flat-blade screw driver, or a 1/4 inch extension both work to retract the pistons.

Next time leave the calipers on the rotors

 

also, they make a tool to screw in calipers. ....