Parallelism

Parallelism is the measurement of the thickness of the rotor at four or more points around the circumference of the rotor. All measurements must be made at the same distance in from the edge of the rotor. The rotor thickness must not vary more than 0.013 mm (0.0005- inch) from any point to point. Rotors exceeding this specification may cause a vibration/ pedal pulsation as the brake pads open and close slightly. Parallelism checks on K1, K2 trucks should also be done with -tool J37620 installed to simulate "as installed" conditions.