Jack up the front of the car and remove the road wheel and disc pads. Examine the surface of the disc for deep scoring or grooving; light scoring is normal, but anything more severe should be addressed by having the disc surface ground, provided the thickness remains within specification; otherwise, a new disc will be required. Check the disc for run-out using a dial gauge, or a reasonable check can be made with feeler blades between the disc face and a fixed point; if the run-out exceeds 0.008 in. (0.2 mm), the disc must be replaced. To remove the disc, first take off the hub assembly, then unscrew the socket-headed screws and lift the disc from the hub. If needed, the disc inner guard plate can be removed by unscrewing the three securing bolts. Reassembly follows the reverse order of disassembly.