You need to remove the fluid from the caliper and the brake pad and clean the interior of the caliper with clean shop towels. Next, remove the piston, direct the compressed air into the caliper fluid inlet, remove the boot, the piston seal with a nonmetal tool, and the bleeder valve. Then clean the bleeder valve, the caliper bore, the caliper passages, and the piston with denatured alcohol. Replace any piston which is scored, corroded, or contains damage to the chrome plating. Replace any caliper bore which is scored, pitted, or corroded. Finally, you can attempt to polish off any light corrosion with a crocus cloth.
By BobGM Specialist
29/10/2022