Brake Rotor/Disc: Testing and Inspection

Measure Disc Thickness
Using a micrometer, measure the disc thickness.

Standard thickness: 28.0 mm (1.102 inch)
Minimum thickness: 26.0 mm (1.024 inch)

Replace the disc if the thickness of the disc is at the minimum thickness or less. Replace the disc or grind it on a lathe if it is scored or is worn unevenly.




Measure Disc Runout
Using a dial indicator, measure the disc runout at a position 10 mm (0.39 inch) from the outside edge.

Maximum disc runout: 0.05 mm (0.0020 inch)

If the disc's runout is at the maximum value or greater, check the bearing play in the axial direction and check the axle hub runout. (See "Steering and Suspension")
If the bearing play and axle hub runout are not abnormal, adjust the disc runout or grind it on a "On-Car" brake lathe.