If the piston is just a solid or hollow cylinder, you can use a pair of big channel locks and an old brake pad to squeeze it back in, if the piston has little cut outs in it you will need to rent a tool that twists the piston back in to place, like a bolt.
You need to turn the piston clockwise and it will slowly retract as you turn.
Use a "C" clamp to fully retract piston into caliper body
Clockwise to retract piston into caliper body
Rotor "Out of Round" when rotating "High" spot will cause piston to retract into caliper body
Rotor "Out of Round" when rotating "High" spot will cause piston to retract into caliper body
Use a "C" Clamp to fully retract the piston into the caliper body
You cant, it needs a 'C' clamp.
There is a 14 mm bolt on back of caliper. Remove this & use a 4 mm Allen wrench to back piston into caliper.
If it is the front brake use a "C" clamp to retract piston If it is the rear and the parking brake is used by this caliper piston is threaded and a special tool (not expensive) available at Sears or auto parts to "screw" piston into caliper body
Remove caliper mounting bolts Slide caliper off rotor Use a "C" clamp to fully retract piston into caliper body If parking brake is used on this caliper piston is threaded and a special tool (not expensive) is required to thread piston into caliper body
On the back of the caliper there should be a bolt its a 14mm you take it out and inside there is a bolt also its Allen key you use and Allen key and retract the caliper. it works on all 626 from 1994 till 2002
One cause is that the cylinder the caliper piston moves in has scores - grooves worn in the cylinder walls that the edge of the piston is catching on. One of the easiest approaches would be to replace the caliper with a remanufactured / rebuilt one.