Trooper LS V6-3.5L (1998)
Brake Rotor/Disc: Testing and Inspection
Rear Brake Rotor
INSPECTION
In the manufacturing of the brake rotor, all the tolerances regarding surface finish, parallelism and lateral runout are held very closely. Maintaining
these tolerances provides the surface necessary to assure smooth brake operation.
Lateral Runout
Lateral runout is the movement of the rotor from side to side as it rotates on the spindle. This could also be referred to as "rotor wobble".
This movement causes the piston to be knocked back into its bore. This results in additional pedal travel and a vibration during braking.
Checking Lateral Runout
1. Adjust the wheel bearing correctly.
2. Attach a dial indicator to some portion of the suspension so that the stem contacts the rotor face about 29 mm (1.14 inch) from the rotor edge.
3. Move the rotor one complete rotation and the lateral runout should not exceed 0.13 mm (0.005 inch).
Maximum Runout: 0.13 mm (0.005 inch)
Parallelism
Parallelism is the measurement of thickness of the rotor at four or more points around the circumference of the rotor. All measurements must be made
22 mm (0.87 inch) from the edge of the rotor.
The rotor thickness must not vary more than 0.010 mm (0.0004 inch) from point to point.
Maximum Parallelism: 0.001 mm (0.0004 inch)
