GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Jimmy - 2WD 🢒 Brakes 🢒 Disc Brakes 🢒 Brake Rotor Refinishing

Important: Do NOT refinish the brake rotors in order to correct any of the following complaints:

   • Brake noise (growl/squeal)
   • Premature brake lining wear
   • Cosmetic or superficial corrosion of the rotor braking surface
   • Rotor discoloration
Refinish the brake rotors ONLY when one or more of the following conditions exist:
   • Severe scoring of the rotor braking surface (groove depth in excess of 1.5 mm (0.060 in)
   • Hot spots on the rotor braking surface
   • Brake pulsation caused by the following:
      - Excessive brake rotor thickness variation. Refer to Component Specifications .
      - Corrosion or pitting that is deeper than the rotor braking surface

The following brake lathes are approved and achieve satisfactory results.

    • Ammco® (off-vehicle)
    • Accu Turn® (off-vehicle)
    • Pro-Cut® (on-vehicle)

Tools Required

J 42450-A Hub Cleaning Kit

  1. Remove the tire and wheel. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.

    2. Notice: Do not allow components to hang from the flexible brake hoses as damage to the hoses may occur. Some brake hoses have protective rings or covers to prevent direct contact of the hose with other chassis parts. Besides causing possible structural damage to the hose, excessive tension could cause the hose rings to move out of their proper locations.

  2. Remove and support the brake caliper. Refer to Front Brake Caliper Replacement
  3. Rear Brake Caliper Replacement
  4. Remove the brake caliper bracket (JC1 System Only). Refer to Brake Caliper Bracket Replacement .
  5. Make a mark on the brake rotor in order to identify the relationship to the hub flange or axle flange (JC1 System Only).

    6. Notice: Whenever the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surface of the rotor and flange with the J 42450 hub cleaning kit. Failure to do this may result in increased lateral runout of the rotor and brake pulsation.

  6. Remove the brake rotor. Refer to Front Brake Rotor Replacement or Rear Brake Rotor Replacement .
  7. Use the J 42450-A in order to clean the wheel bearing/hub or axle flange (JC1 System Only).
  8. Use a micrometer in order to measure the thinnest point of the brake rotor. If the thinnest point of the brake rotor exceeds the brake rotor minimum thickness after refinishing, do NOT refinish the brake rotor. Replace the brake rotor. Refer to Component Specifications .
  9. Use the J 41013 Rotor Resurfacing Kit (or equivalent) in order to THOROUGHLY clean the rust from the brake rotor flange.
  10. Install the brake rotor for refinishing.
    11. • If you use the Accu Turn® or Ammco® (off-vehicle) brake lathe, install the brake rotor to the brake lathe. Refer to the brake lathe manufacturer's operating instructions.
    • If you use the Pro-Cut® (on-vehicle) brake lathe:
         1. Install the brake rotor to the vehicle. Align the brake rotor to the hub or axle flange on vehicles with the JC1 system by using the marks made during the removal procedure. Refer to Front Brake Rotor Replacement or Rear Brake Rotor Replacement .
         2. Install the Pro-Cut® brake lathe to the vehicle. Refer to the brake lathe manufacturer's operating instructions.
  11. Refinish the brake rotor. Refer to the brake lathe manufacturer's operating instructions.

    12. Important: Failure to obtain the best possible braking surface finish may cause the vehicle to stop with difficulty.

  12. After machining the rotor, use 120 grit aluminum oxide sandpaper and a non-directional rotor finisher (if available) in order to create a non-directional braking surface.
  13. Clean the braking surfaces with denatured alcohol or with a suitable brake cleaner.
  14. If you use the Accu Turn® or Ammco® (off-vehicle) brake lathe:
    15. 14.1. Remove the brake rotor from the brake lathe.
    14.2. Install the brake rotor to the vehicle. Align the brake rotor to the hub or axle flange on vehicles with the JC1 system by using the marks made during the removal procedure. Refer to Front Brake Rotor Replacement or Rear Brake Rotor Replacement .
  15. Install the brake caliper bracket (JC1 System Only). Refer to Brake Caliper Bracket Replacement .
  16. Install the brake caliper. Refer to Front Brake Caliper Replacement
  17. Rear Brake Caliper Replacement

    18. Notice: Improperly tightened wheel bolts or nuts can lead to brake pulsation and rotor damage. In order to avoid expensive brake repairs, evenly tighten the wheel bolts or nuts to the proper torque specification.

  18. Install the tire and wheel. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.