To assist and repair the Brake Disc, start by using the
Wheel Hub resurfacing kit (J 42450-A) to clean any rubble or erosion from the corresponding surface of the hub/axle flange. Next, clean off any rust or corrosion from the mating side of the Brake Disc and the mounting surface as well, using the rotor resurfacing kit (J 41013). Check both mating surfaces for the presence of any foreign particles and debris. Mount the Brake Disc to the brake lathe as it is directed by the manufacturer and ensure that all the attachments and adapters are clean. Securely position any vibration dampening attachments and then the lathe brake, slowly advance the cutting tools until they indicate the Brake Disc friction surfaces. In the disc, examine the witness mark. If its length is about three-fourthes and more on each side around the surface, the disc is properly mounted. If not, check by re-mounting the disc and following lathe manufacturer's instructions in refinish it. Inspect the disc thickness after each cut and when it is of the maximum thickness after refinishing, replace the disc. To get a non-directional finish, use the recommended speed setting, and apply the finish with the help of either a non-directional finishing tool on which is mounted 120 grit aluminum oxide sandpaper, or a sanding block of 150 grit aluminum oxide sandpaper. Clean each friction surface if necessary using denatured alcohol, an approved brake cleaner, and then remove the disc from the lathe. Finally measure the assembled lateral runout (LRO) of the Brake Disc to ensure maximum performance from disc brake will be done, and in the case of lro exceeding specification, adjust.