Q: How do I properly inspect, measure, and refinish brake discs?
A: To inspect the brakes, start by loosening the wheel lug nuts and raising the vehicle on jackstands. Remove the brake caliper, suspending it out of the way with wire. Visually inspect the disc surface for score marks and damage, checking both sides. If pulsating has been noticed during braking, suspect disc runout. To check runout, reinstall the lug nuts and use a dial indicator to measure the reading, ensuring it does not exceed the allowable limit. If necessary, refinish the disc. It is important to not machine the disc below the specified minimum thickness, which can be checked with a micrometer. For removal, remove the caliper mounting bracket and the lug nuts if they were reinstalled. Mark the disc for reinstallation and remove the retaining screw. During installation, wire-brush the backside of the disc and clean the hub face. Apply high-temperature anti-seize and align the index marks before tightening the retaining screw. Install the caliper mounting bracket and caliper, tightening the bolts to the proper torque. Lower the vehicle, tighten the lug nuts, and depress the brake pedal to bring the pads into contact with the disc. Bleeding is only necessary if the brake hose was disconnected. Finally, carefully check the brake operation before driving the vehicle.