GM 19303830
Rotor

Start work on replacing the rear Brake Disc through vehicle lifting followed by proper support. Secure the brake caliper with heavy mechanic wire when disconnecting it from its mount but keeping the hydraulic hose attached to avoid damaging the hose and creating brake fluid leaks. Use mechanic's wire to lift the brake and bracket assembly as one device before you take out the Brake Disc. When installing a new disc you must eliminate all surface rust and contaminants from the wheel bearing flange and Brake Disc seatings to avoid developing unstable side-to-side movement and brake vibrations. You should use rotor resurfacing kit j 41013 to remove wheel hub surface rust or corrosion. Place the new disc first and add the caliper bracket afterward. Put back the tire and wheel before lowering your car. Before working on a new disc always wipe off its friction area with goodwrench brake parts cleaner (P/N 123777981) or equivalent and check that the surface is spotless. Never apply gasoline or oil-based cleaners that can harm the disc.

The brake disc requires refinishing only when specific damage elements appear like abundant corrosion, brown-black discoloration, or damage from corrosion particles. When resurfacing is needed use J 41013 to clean wheel bearing flange corrosion and J 42450-A to clean the brake disc hub. Follow brake lathe maker guidelines when installing the brake disc and verify vibration control fixtures remain locked in place. Put the lathe into motion while lowering the cutting tools until they touch the disc area and verify good tool positioning using the witness mark. Follow lathe instructions while restoring the disc and test its thickness after every cutting step until minimum limits are reached on new discs. Use the suggested speed range when finishing non-directional surfaces and use 120 grit aluminum oxide sandpaper with the tool or 150 grit sandpaper with a block for proper results. After sanding steps you must clean each brake surface by wiping with denatured alcohol or equivalent brake cleaner solution.

Per instructions available in goodwrench brake parts cleaner kit (P/N 123777981), remove the protective coating from new disc friction faces by wiping with specialized cleaning solution and lint-free cloths. Never use gasoline, kerosene, or oil-based products that may contaminate the disc. Start by safely lifting the vehicle and detach the tire and wheel. Keep the brake caliper safe when you remove it from its mount without disconnecting the hydraulic brake hose through wire support. First secure the brake caliper and bracket as one unit using mechanic's wire. After that remove the Brake Disc from the vehicle. Remove all rust or foreign material from the wheel bearing flange and Brake Disc contact areas by using j 41013 disc resurfacing kit product. Install the new Brake Disc first and put on the caliper bracket afterward before replacing the tire and wheel which needs to be done below vehicle level.

Before starting work you should lift the vehicle off the ground and provide proper support. Take out the tire and wheel and then proceed to remove the caliper bracket. You need to launder the metal parts between the Brake Disc and hub bearing flange before taking out the Brake Disc. Start by installing the new Brake Disc before placing back the caliper bracket. End your task by fixing the tire and wheel back on and letting the vehicle down.

You must check brake disc thickness variation first because brake pulsation could result from exceeding the maximum buildup. When the assembled LRO exceeds permitted limits it leads to brake disc thickness changes which typically occur during 4,800 to 11,300 km (3,000 to 7,000 mi) of travel. To correct assembled LRO, consider the following methods based on the specific vehicle being repaired: the indexing method is effective for small LRO exceedances of 0.025-0.127 mm (0.001-0.005 in) and aims to match high spots to low spots between related components; the correction plate method involves adding a tapered plate between the brake disc and the hub/axle flange to correct LRO exceeding the specification by up to 0.23 mm (0.009 in); and the on-vehicle brake lathe method refines the brake disc while compensating for LRO to bring it within specifications. Other parts likely need adjustment when standard procedures fail to solve brake disc runout problems.

The Brake Disc needs j 41013 rotor resurfacing kit and j 42450-a Wheel Hub resurfacing kit to perform services and repairs. Before refinishing check the disc thickness to ensure it will still pass the needed specification after the work finishes. You need to refinish brake discs only when their thickness differs too much from defined limits plus shows intense corrosion or pitting and extensive blue discoloration beyond specified points. Use j 42450-a to remove hub/axle flange rust and corrosion before cleaning Brake Disc mating and mounting surfaces with j 41013. Check both surface ends to find and remove outside objects. Install the Brake Disc to the brake lathe as described by the manufacturer while keeping all attachments free of dirt. Set the tools against disc friction surfaces while the lathe spins and verify tool placement by inspecting the marks on the disc. If necessary, re-mount the disc. Use the lathe as explained in the manufacturer manual while checking the disc thickness after each cut. The disc must be replaced when refinishing shows its thickness beyond the minimum allowed limits. Stick to the recommended speed when sanding the friction surface using non-directional sanding media either 120 aluminum oxide sandpaper or 150 sanding blocks. Use denatured alcohol or brake cleaner to clean torque surfaces and take the lateral runout measurement of the disc parts to modify alignment when the reading deviates from standards.

Install the caliper bracket.

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

Clean each friction surface with denatured alcohol or an equivalent brake cleaner.

Install the brake rotor to the hub/axle flange using the matchmark for proper orientation.

Apply the recommended speed setting, using 120 grit aluminum oxide sandpaper with a non-directional finishing tool, or 150 grit aluminum oxide sandpaper with a sanding block if not.

To eliminate any rust or contaminants, as neglecting this step may lead to lateral runout and brake pulsation.

Check the brake rotor thickness; if it falls below the minimum allowable thickness, replace the rotor.

Use heavy mechanic's wire to support the brake caliper and prevent damage to the hydraulic flexible brake hose.

Reinstall the caliper bracket.

Repeat the indexing and measurement process until the best assembled LRO measurement is achieved, and matchmark the final rotor location to the wheel studs if the orientation differs from the original.

Remove the caliper bracket bolts without disconnecting the brake flexible hose bolt, and take off the brake caliper and caliper mounting bracket as an assembly from the suspension knuckle.

Refinishing is required if there is excessive corrosion, pitting, cracks, heat spots, excessive bluing discoloration, scoring beyond maximum allowable specifications, lateral runout exceeding specifications, or thickness variation beyond specifications.

With the lathe running, bring in the cutting tools to contact the rotor friction surfaces, check the witness mark for proper mounting, and follow the lathe manufacturer's instructions to refinish the rotor, inspecting thickness after each cut.

Remove the caliper bracket bolts without disconnecting the brake flexible hose bolt, then remove the brake caliper and caliper mounting bracket as an assembly from the suspension knuckle.

Follow the lathe manufacturer's instructions to refinish the rotor, inspecting thickness after each cut, and replace the rotor if it exceeds the minimum allowable thickness after refinishing.

The rotor must be replaced.

Reinstall the caliper bracket.

Utilize the Wheel Hub/Flange Resurfacing Kit (J 42450-A).

Clean any rust or contaminants from the wheel bearing flange and the brake rotor mating surfaces.

Support the brake caliper with heavy mechanic's wire.