First remove the brake caliper from the vehicle but keep your fingers away from the
Piston during compressed air use to stay safe. Use clean fabric padding over inside caliper housing while removing pistons and give them space to move by applying low-pressure compressed air through the fluid access point until the pistons move out naturally. Professionalism in removing the dust boot seal from Piston as well as Piston seal from caliper unit combines plastic tool to extract these seals for disposal. Take out the bleeder valve equipment from its position in the caliper. Thoroughly clean the Piston bore and seal counterbore of the caliper with denatured alcohol or equivalent followed by filtered non-lubricated air blowing. Examine the caliper chamber for problems with its surface including cracks, damage, extreme rust damage or corrosion. Light surface rust may be cleansed with fine sandpaper but major quality defects require replacement of the whole caliper device. Replace the caliper Piston when you detect damage to chrome plating or find cracking and scoring on its surface. Dip a new Piston seal into delco supreme 11 brake fluid (GM part 12377967) from a sealed container then put it into the caliper bore. Insert the new caliper Piston into the bore space then put thedust boot seal on top of it. A dust boot seal installer designed for calipers (or a similar tool) should push the rubber seal fully into its counterbore of 78.08 mm (3.074 inch) and Piston bore of 63.52 mm (2.501 inch). Afterward, put the bleeder valve into the caliper before connecting its cap and making sure the valve remains tight. Then place the caliper back on the vehicle.