W 150 Ramcharger V8-360 5.9L (1991)
4. Rotate the bezel on the dial indicator such that "0" is at the low deflection point.
5. Again rotate the rotor at least one complete turn and observe the needle deflection. Total needle deflection will equal lateral runout.
6. Readjust the wheel bearings.
MINIMUM THICKNESS
The thickness of a rotor is important for two reasons:
1. Rotors which are too thin are not able to properly absorb and release heat during heavy braking. This results in reduced braking capacity and
brake fade.
2. Rotors worn below minimum thickness in combination with worn pads/linings can result in the caliper piston extending too far becoming
cocked or jammed.
Rotor thickness should be measured at the thinnest point on the rotor. Any rotor which is worn below its minimum thickness should be replaced.
For accurate measurements, it is best to remove the caliper to allow for complete access to the inboard side of the rotor.
For more information on how to use a disc brake micrometer see Fundamentals and Basics. See: Fundamentals and Basics
PARALLELISM
Parallelism is the measurement of the thickness of the rotor at 12 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.
