Lexus 42431-33130 Disc, Rear

Loosen the wheel lug nuts, raise the vehicle, support it on jackstands, then remove the wheel and install the lug nuts to hold the disc in place. If working on the rear brake disc, release the parking brake. Remove the brake caliper, but there's no need to disconnect the brake hose. Suspend the caliper with wire, then detach the caliper mounting bracket. Visually inspect the disc for damage; light scratches and shallow grooves are typical, but deep scoring may require professional refinishing. Check for disc run out using a dial indicator set near the disc's edge. If the reading exceeds the maximum allowable, consider machining or replacing the disc. Professionals often advise disc resurfacing when changing pads, ensuring a smooth, flat surface. If not resurfacing, de-glaze the disc with sandpaper or emery cloth in a swirling motion. Never machine the disc below its minimum allowable thickness, indicated on the disc's inside. To determine thickness, use a micrometer. To remove the disc, take off the holding lug nuts and slide the disc off. For stubborn rear discs, adjust the parking brake shoes using the adjuster wheel. For installation, position the disc over the studs, attach the caliper mounting bracket, then the caliper. If the brake hose remained attached, there's no need to bleed the system. Finally, reinstall the wheel and lug nuts, lower the vehicle, tighten the lug nuts, and press the brake pedal a few times to align the brake pads with the disc. Always test brake functionality before driving.