It is very important that you make the brake rotor surface non-directional. Dress the brake surfaces with a sanding disc tool such as the Ammco 8750 Safe Swirl Disc Rotor Grinder, Accu Turn 433179 Non-Directional Swirl Finisher, or equivalent. Use 120 grit aluminum oxide sandpaper.
Important: The finished brake rotor surface should be as close to that of a new brake rotor as possible. Failure to obtain the best possible brake rotor finish can affect braking performance.
Sand each brake rotor surface using moderate pressure for a minimum of 60 seconds.
If the brake lathe is not equipped with an adequate non-directional finishing tool, use a sanding block with 150 grit aluminum oxide sandpaper.
Important: The finished brake rotor surface should be as close to that of a new brake rotor as possible. Failure to obtain the best possible brake rotor finish can affect braking performance.