GM 18027886 Front Brake Rotor Assembly

Raise the vehicle and place it securely on jackstands, then remove the appropriate wheel and tire. Next, remove the brake caliper assembly, ensuring not to disconnect the brake hose on front disc brakes; after removing the caliper mounting bolts, hang the caliper out of the way using a piece of wire, avoiding any strain on the brake hose to prevent damage. Inspect the Brake Disc surfaces for light scoring or grooving, which is normal, but be cautious of deep grooves or severe erosion, especially if pulsating has been noticed during brake application, as this may indicate disc run out. Attach a dial indicator to the caliper mounting bracket, turn the Brake Disc, and note the amount of run out, checking both inboard and outboard surfaces; if the run out exceeds the maximum allowable, the Brake Disc must be removed and taken to an automotive machine shop for resurfacing. Measure the thickness of the Brake Disc with a micrometer, and if it is less than the minimum specified, replace it with a new one, also measuring the disc thickness at several points to check for variations; any variation over 0.0005-inch may cause pedal pulsations during brake application, and if this condition exists while the disc thickness is above the minimum, the Brake Disc can be removed for resurfacing. For the removal and installation of the front Brake Disc, check and repack the wheel bearings, and note that the Brake Disc on rear wheel disc brake models can be pulled off after the caliper is removed.