Doing the brakes on my dart and now they are locking up as I tighten the caliper slide bolts. Were working fine before, just worn thin so I thought I would replace them. Pistons squeezed in fine and loaded caliper went right onto the rotor. the more I tighten the caliper bolts the tighter the brakes get until the rotor is locked up. Have only done one side so for and thought I'd better figure it out. 1970 dart front disc rear drum manual brakes. Thanks.