I bot. a 1993 883 Hugger and am trying to get the rear brake off. I pulled both bolts and the caliper is free but right before it comes off the rotor it acts like it hit a hidden bolt. I was told the rotor was probably warped and the caliper piston was hitting the edge of the rotor. I put a straight edge on the roter and it seems straight. It unscrewed the brake line and lightly tapped on the caliper to push the piston in with a rubber hammer but it still hits and stops on something solid just before it comes off. Any guess what is wrong?

 

mine is hard to get off sometimes i just yank it no damage and i cant see what cuases it