The proper method is how it is described originally below with the removal of the cap on the back of the caliper and turning in the Allen screw which retracts the E-brake adjuster inside the caliper. There are some cars where you rotate the piston itself into the caliper, if you have that type of caliper you need a cheap tool from the parts store which has pins that locate in the holes in the piston and you put a socket on the other end to rotate it. If you use pliers on the caliper piston you will score it and screw up the seal.
14yr ASE Certified Technician.
AnswerThere is a small bolt in the center of the backside of the caliper. Remove that bolt and you will see a small Allen head screw inside it. Loosen that screw as you apply moderate pressure to the front of the piston.If you can't compress the piston with a C clamp back in to position to fit the new brake pads I would suggest replacing the caliper completely.
You need a tool mostly used on ford cars that turns the piston while pressing it.
There is a set screw on the back of the Caliper that you turn to compress the piston. You use the same set screw to adjust the brakes when you change brake pads.
Loosen something on the brake if you tighten it will get worse screw caliper piston in or out with caliper tool. they are like that for the park brake function
First you have to take the calipers off. Then compress the piston and lift the caliper off. Then you pull remove the springs to get the pad off.
Remove the wheels, then the bolt that holds the pin that holds the caliper on. Drive the pin out then depress the piston completely in the caliper. Make sure to use the anti squeek grease or shims when reassembling it.
Clockwise to retract piston into caliper body
You can use a C-clamp to compress the caliper on just about any vehicle. You might want to place some rags near the Brake Master cylinder because brake fluid will travel back into it from what is left over in the brake lines. If you don't, you will spill brake fluid onto the floor.
Once you take the caliper off , you will need a C-clamp to compress the piston back into the caliper . Make sure you leave the old pad on top of the piston to help it go straight back into the housing , be careful and do not let the piston go in crooked , it will get stuck . You may also need to get a small kit , that has the little springs that hold the retaining pins in , if you break one .
Have noticed that Ford still uses the screw style pistons on the rear calipers. To retract the piston use either a caliper/piston tool or a set of needle nose pliers. Turn the piston clockwise to get it back in but take note of the position of the grooves as they normally need to align so that a imaginary straight line through the grooves points to the center of the caliper.
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.
Turn the piston clockwise and it scews itself in...