K 1500 Truck 4WD V8-5.7L VIN R (1997)
Brake Rotor/Disc: Testing and Inspection
Brake Rotor Lateral Runout Check
The best way to check lateral runout is with the wheels still installed on the vehicle. This gives a much more accurate reading of the Total Indicated
Runout (T.I.R.) under real braking conditions. If equipment is not available to perform the check with the wheels installed, the next best reading can be
made with the wheels removed but the caliper still installed.
1. Clean rotor surface.
2. If the wheel must be removed, reinstall the wheel lug nuts to retain the rotor. Tighten the nuts in sequence to the correct torque. Failure to properly
tighten wheel nuts can cause pedal pulsation and/or front end vibration during brake applications.
Inspecting For Lateral Runout
3. Fasten a dial Indicator to the steering knuckle so the indicator button contacts the rotor surface about 13 mm (0.5 inch) from the outer edge.
4. Set the dial indicator to zero.
5. Turn the wheel one complete revolution and observe the runout indicated on the dial.
6. The T.I.R. must not exceed 0.08 mm (0.003 inch).
7. If lateral runout is not within specifications, refinish or replace the rotor as necessary.
NOTE: In some cases, excessive lateral runout can be improved by indexing the rotor on the hub one or two bolt positions from the original position. If
lateral runout cannot be corrected by indexing the rotor, check the hub and bearing assembly for excessive lateral runout or looseness. If the hub and
bearing assembly lateral runout exceeds 0.040 mm (0.0015 inch), repair or replace and bearing assembly.
NOTE: When the brake rotor has been separated from the wheel bearing flange, remove all rust or foreign material from the mating surfaces of the
wheel bearing, flange and rotor. Failure to do so can result in increased lateral runout and brake pulsation.
