Before installing your new brake pads, you’ll need to compress the piston back inside the caliper. The caliper piston has extended as the pad material wears. With new thicker pads, you must return the piston back inside the caliper body to give the thicker pads room for installation. Using a piston compressor or a large C-clamp, place a used brake pad over the face of the piston to protect the surface from marring, and begin compressing the piston. As you turn the handle on the clamp, it will in