GM 91177048
Caliper

A brake caliper overhaul starts by lifting and supporting the vehicle followed by tire removal. Detachment of the caliper from the vehicle requires attention to fingers and safety eyewear against possible harm. Apply controlled air pressure until the Piston clears the bore then drop a hardwood block or shop cloth inside the caliper before it can move. To remove the Piston blow compressed air through the caliper brake hose connector hole before removing the rubber boot from the caliper groove. A flat plastic tool will aid in Piston seal extraction and the caliper pin bolts require removal with bleeder valve and boots. Pay attention to brake fluid because it can both irritate the skin and eyes. If you experience contact with brake fluid be sure to thoroughly wash the contaminated surface with water then visit a doctor if you swallow any fluid. Protect your vehicle's electrical wiring and painted surfaces against brake fluid corrosion by covering them with shop cloths and fitting them in suitable receptacles. The caliper slide bushings and Piston and caliper cylinder bore and set ring should receive a clean with brake fluid before studying the chrome plating and corrosion condition and potential scoring damage on the Piston to warrant a replacement component. Inspect the caliper cylinder bore to detect scoring and pitting and corrosion then remove light corrosion with crocus cloth polishing; check the bore again. Continued corrosion marks the need for a new caliper replacement. New caliper pin bolts along with boots must be installed before fitting a new Piston seal into the caliper bore and positioning it with a new Piston boot on the Piston ahead of Piston insertion into the caliper. Push the Piston boot through the caliper groove while paying attention to avoid Piston cylinder damage. Test the boot fitment by exerting pressure on the Piston. Mount the Piston inside the caliper bore while pushing it through while installing the bleeder valve without tightening it. After vehicle reinstallation of the caliper and tire and wheel assembly the vehicle lowers while performing brake system bleaching procedures.

Remove the front brake hose fitting and the 2 washers from the caliper.

Push the piston into the caliper to seat it in the bore, then install the bleeder valve without tightening it.

Raise and support the vehicle, then remove the tire and wheel assembly.

Remove the rubber boot from the caliper groove, use a flat plastic tool to take out the piston seal, and remove the bleeder valve along with the caliper pin bolts and boots.

Raise and support the vehicle, then remove the tire and wheel assembly.