GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 G8 🢒 Brakes 🢒 Disc Brakes 🢒 Brake Rotor Assembled Lateral Runout Correction - On Vehicle Lathe

Danger: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.

Warning: Refer to Safety Glasses Warning in the Preface section.

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

Note: 

   • Brake disc thickness variation must be inspected before inspecting for assembled lateral runout (LRO). Thickness variation exceeding the maximum acceptable level can cause brake pulsation. Refer to Brake Rotor Thickness Variation Measurement.
   • Brake disc assembled LRO exceeding the maximum allowable specification can cause thickness variation to develop in the brake disc over time, usually between 10 000-20 000 km (6,213-12,427 mi). Refer to Brake Rotor Assembled Lateral Runout Measurement.
   • Before refinishing a brake disc, the brake disc must first be inspected for adequate thickness to allow the brake disc to be refinished and remain above the minimum allowable thickness after refinish specification. Refer to Brake Rotor Thickness Measurement.

  1. Make sure that the brake caliper and brake caliper anchor plate that are already being supported, are clear from contacting any rotating components, such as the brake disc.
  2. Remove the dial indicator and the wheel 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 disc to make sure that there are no foreign particles or debris remaining.
  4. Set up the lathe, following the manufacturer instructions.
  5. Refinish the brake disc, following the brake lathe manufacturer instructions.
  6. After each successive cut, inspect the brake disc thickness. Refer to Brake Rotor Thickness Measurement.
  7. If at any time the brake disc exceeds the minimum allowable thickness after refinish specification, the brake disc must be replaced. After replacing the brake disc, proceed to step 10.
  8. After refinishing the brake disc, use the following procedure in order to obtain the desired non-directional finish:
    9. 8.1. Follow the brake lathe manufacturer 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 disc with denatured alcohol, or an equivalent approved brake cleaner.
  9. Remove the lathe from the vehicle.
  10. Measure the assembled LRO of the brake disc. Refer to Brake Rotor Assembled Lateral Runout Measurement.
  11. If the brake disc assembled LRO measurement still exceeds the maximum allowable specification, refer to Brake Rotor Assembled Lateral Runout Correction.
  12. If the brake disc assembled LRO is within specification, install the brake caliper and depress the brake pedal several times to secure the brake disc in place before removing the dial indicator and the wheel nuts.