Brake Rotor/Disc: Service and Repair

NOTE: Any servicing of the rotor requires extreme care to maintain the rotor to within service tolerances to ensure proper brake action.

REFINISHING INFORMATION

Refacing Brake Rotor:

Fig 7 Refacing Brake Disc -- Final Finish:

If the rotor surface is deeply scored or warped, or there is a complaint of brake roughness or pulsation, the rotor should be resurfaced or refaced.

Brake Rotor Refinishing Limits:

The illustrated chart shows the location of measurements and specifications when servicing the rotor.

Minimum Brake Rotor Thickness Markings:

NOTE: All rotors have markings for minimum allowable thickness cast on an un-machined surface of the rotor.

This marking includes 0.76 mm (0.030 inch) allowable rotor wear beyond the recommended 0.76 mm (0.030 inch) of rotor refacing.

The collets, shafts and adapters used on the brake lathe and the bearing cups in the rotor MUST be clean and free from any chips or contamination.

When mounting the rotor on the brake lathe, strict attention to the brake lathe manufacturer's operating instructions is required.

If the rotor is not mounted properly, the lateral runout will be worse after refacing or resurfacing than before.

REFACING BRAKE ROTOR
Refacing of the rotor is not required each time the brake pads are replaced.

When refacing a rotor the required 0.10 mm (0.004 inch) Total Indicator Reading (TIR) and 0.013 mm (0.0005 inch) thickness variation limits MUST BE MAINTAINED. Extreme care in the operation of rotor turning equipment is required.

The use of a double straddle cutter that machines both sides of the rotor at the same time is highly recommended.

RESURFACING BRAKE ROTOR
This operation can be used when rotor surface is rusty, has lining deposits or excessive lateral runout or thickness variation is evident.

A sanding rotor attachment will remove surface contamination without removing much rotor material.

It will generally follow variations in thickness that are in the rotor.