Refinishing Brake Rotors

- Tools Required
- J 37704 Disc Brake Lathe

The following two procedures are recommended and achieve adequate results using two different off-vehicle disc brake lathes. If any other lathe is used, follow that lathe's instructions and recommendations:

Ammco Brake Lathe
Refer to the manufacturer's instructions for all initial setup and cutting procedures.

Accu Turn Brake Lathe GM Dealer Equipment (One Cut Refinishing Procedure)
Refer to the manufacturer's instructions for all initial setup and cutting procedures.

Nondirectional Finishing
Ensure that the rotor surface is nondirectional by dressing the rotor surfaces with one of the following sanding disc tools (or equivalent) using 120 grit aluminum oxide sandpaper:
- Ammco 3750 Safe Swirl Disc Rotor Grinder
- Accu Turn 433170 Non-Directional Swirl Finisher
Use the following procedure for nondirectional finishing:
1. Sand each rotor surface with moderate pressure for a minimum of 60 seconds.
If the brake lathe is not equipped with an adequate nondirectional finishing tool, use a sanding block with 150 grit aluminum oxide sandpaper.
2. 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.
3. 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.