FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Brake Disc Thickness Check

BRAKE DISC THICKNESS CHECK

CAUTION: Take care not to contact the parts or tools to the caliper because the paint of caliper will be scratched. And if there is brake fluid on the caliper, wipe it off quickly.





1. Using a micrometer, measure disc thickness at eight positions, approximately 45 degrees apart and 10 mm (0.39 inch) from the outer edge of the disc
Standard value:
32.0 mm (1.26 inch)
22.0 mm (0.87 inch)
Minimum limit:
29.8 mm (1.17 inch)
20.4 mm (0.80 inch)

NOTE: Thickness variation (at least 8 positions) should not be more than 0.015 mm (0.0006 inch).

2. If the disc thickness is less than the limits, replace it with a new one





CAUTION:
^ After a new brake disc is installed, always grind the brake disc with on-the-car type brake lathe. If this step is not carried out, the brake disc runabout exceeds the specified value, resulting in judder.
^ When the on-the-car type lathe is used, first install a M12 flat washer on the stud bolt in the brake disc side according to the figure, and then install the adapter. If the adapter is installed with M12 flat washer not seated, the brake disc rotor may be deformed, resulting in inaccurate grinding.
^ Grind the brake disc with all wheel nuts diagonally and equally tightened to the specified torque 100 Nm (74 ft. lbs.). When all numbers of wheel nuts are not used, or the tightening torque is excessive or not equal, the brake disc rotor or drum may be deformed, resulting in judder.

3. If thickness variation exceeds the specification, turn rotor with an on-the-car type brake lathe ("Accuturn-8750" or equivalent)
If the calculated final thickness after turning the rotor is less than the standard value replace the disc.