A: Loosen the brake line fitting and remove the two bolts from the backing plate. Remove the brake line fitting, push rods, and dust seals. Press in one piston and remove the cup spring, cup, and piston. Clean the wheel cylinder, pistons, and spring. Inspect the cylinder bore and pistons. Lubricate the bore and attach the cup expanders. Insert the spring assembly, cup, and pistons. Attach the dust boot assembly and reattach the brake line. Install the two wheel cylinder mounting bolts and tighten the flare nut.