Brake Disc Machining

WARNING: THE ELECTRICAL POWER TO THE AIR SUSPENSION SYSTEM MUST BE SHUT OFF PRIOR TO HOISTING, JACKING OR TOWING AN AIR SUSPENSION VEHICLE. THIS CAN BE ACCOMPLISHED BY TURNING OFF THE AIR SUSPENSION SWITCH. FAILURE TO DO SO CAN RESULT IN UNEXPECTED INFLATION OR DEFLATION OF THE AIR SPRINGS, WHICH CAN RESULT IN SHIFTING OF THE VEHICLE DURING THESE OPERATIONS.

CAUTION: Do not install brake discs that are less than the minimum thickness specified. Do not machine a brake disc below the minimum thickness specification.

1. Check wheel bearing end-play and correct as necessary.
2. Remove the tire and wheel.

NOTE: Begin at the front of the vehicle unless the vibration has been isolated to the rear.

3. Remove the brake caliper.
4. Measure and record the brake disc thickness. Install a new brake disc if the thickness after machining will be at or below specification. The specification is molded into the brake disc. Do not machine a new brake disc.
5. For vehicles with a two-piece hub and brake disc assembly:
^ Match-mark before disassembly.
^ Remove the brake disc.
^ Using a die grinder with a mild abrasive (Scotch Brite(R) type), remove any rust or corrosion from the hub and brake disc mounting surfaces.
^ Align the match-marks and reinstall the brake disc on the hub.

6. Using the special tool, machine the brake discs. Follow the manufacturer's instructions. After machining, make sure the brake disc still meets the thickness specification.

CAUTION: Do not use a bench lathe to machine brake discs.

NOTE: The depth of cut must be between 0.10 and 0.20 mm (0.004 and 0.008 inch). Lighter cuts will cause heat and wear. Heavier cuts will cause poor brake disc surface finish.

7. Using a dial indicator, verify that the brake disc lateral runout is now within specification.
8. Remove the special tool hub adapter.
9. Remove any remaining metal chips from the machining operation.
10. For vehicles with a two-piece hub and brake disc assembly:
^ Remove the brake disc from the hub.
^ Remove any remaining metal chips from hub and brake disc mounting surfaces and from the ABS sensor.
^ Apply a high temperature anti-seize lubricant to the mounting surfaces.
^ Using the match marks, mount the brake disc on the hub.

11. Install the caliper.
12. Test the system for normal operation.