Non-Directional Finishing

It is very important that the rotor surface be made nondirectional by dressing the rotor surfaces with a sanding disc tool such as Ammco 8750 Safe Swirl Disc Rotor Grinder, Accuturn 433179 Non-Directional Swirl Finisher, or equivalent, using 120 grit aluminum oxide sandpaper. Sand each rotor surface with moderate pressure for the minimum of 60 seconds. If the brake lathe is not equipped with an adequate non-directional finishing tool, an alternate method is to use a sanding block with 150 grit aluminum oxide sandpaper. With the rotor turning at the equipment manufacturer's highest recommended cutting speed, sand each rotor surface for a minimum of 60 seconds using moderate pressure. After the rotor has been sanded, clean each surface with denatured alcohol or a suitable brake cleaner. The finished rotor surface should be as close to that of a new rotor as possible. Failure to obtain the best possible rotor finish may affect braking performance.