Non-Directional Finishing

It is very important that the rotor surface be made non-directional by dressing the rotor surfaces with a sanding disc tool, such as AMMCO Model 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 a 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 as possible to that of a new rotor. Failure to obtain the best possible rotor finish may affect braking performance.