Initial Inspection and Diagnostic Overview

Manufacturers closely hold brake rotor tolerances. These tolerances include flatness of the braking surfaces, parallelism, and lateral runout.
Maintaining the close tolerance on the shape of the braking surface prevents brake roughness or pulsation. The surface finish must be maintained at 60 Ra roughness or less.
Control the braking surface finish in order to avoid the following conditions:
- Hard pedal application
- Excessive brake fade
- Brake and steering pulls
- Erratic brake performance

Controlled braking surface finish can prolong the life of the brake lining. Light scoring of the rotor braking surface not exceeding 1.5 mm (0.06 inch) in depth is normal and will not damage the brake operation.