GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Corvette 🢒 Brakes 🢒 Disc Brakes 🢒 Brake Rotor Assembled Lateral Runout Correction - On Vehicle Lathe

Tools Required

J 45101-100 Conical Brake Rotor Washers

Caution: Refer to Brake Dust Caution in the Preface section.

Important: 

   • Brake rotor thickness variation MUST be checked BEFORE checking for assembled lateral runout (LRO). Thickness variation exceeding the maximum acceptable level can cause brake pulsation. Refer to Brake Rotor Thickness Variation Measurement.
   • Brake rotor assembled lateral runout (LRO) exceeding the maximum allowable specification can cause thickness variation to develop in the brake rotor over time, usually between 4 800-11 300 km (3,000-7,000 mi). Refer to Brake Rotor Assembled Lateral Runout Measurement.

  1. Ensure that the caliper and caliper bracket that are already being supported, are clear from contacting any rotating components, such as the brake rotor.
  2. Remove the J 45101-100 and the lug nuts that were installed during the assembled LRO measurement procedure and/or the indexing correction procedure.
  3. Inspect the mounting surface of the hub/axle flange and the brake rotor to ensure that there are no foreign particles or debris remaining.
  4. Set up the lathe, following the manufacturer's instructions.
  5. Refinish the brake rotor, following the brake lathe manufacturer's instructions.
  6. After each successive cut, inspect the brake rotor thickness. Refer to Brake Rotor Thickness Variation Measurement.
  7. If at any time the brake rotor exceeds the minimum allowable thickness after refinish specification, the brake rotor must be replaced. After replacing the rotor, proceed to step 10.
  8. After refinishing the brake rotor, use the following procedure in order to obtain the desired non-directional finish:
    9. 8.1. Follow the brake lathe manufacturer's recommended speed setting for applying a non-directional finish.
    8.2. Using moderate pressure, apply the non-directional finish:
       • If the lathe is equipped with a non-directional finishing tool, apply the finish with 120-grit aluminum oxide sandpaper.
       • If the lathe is not equipped with a non-directional finishing tool, apply the finish with a sanding block and 150-grit aluminum oxide sandpaper.
    8.3. After applying a non-directional finish, clean each friction surface of the brake rotor with denatured alcohol, or an equivalent approved brake cleaner.
  9. Remove the lathe from the vehicle.
  10. Measure the assembled LRO of the brake rotor. Refer to Brake Rotor Assembled Lateral Runout Measurement.
  11. If the brake rotor assembled LRO measurement still exceeds the maximum allowable specification, refer to Brake Rotor Assembled Lateral Runout Correction.
  12. If the brake rotor assembled LRO is within specification, install the brake caliper and depress the brake pedal several times to secure the rotor in place before removing the J 45101-100 and the lug nuts.