Brake Rotor/Disc: Testing and Inspection

1. Raise the car and remove the front wheels.
2. Start by control measuring on one side. Press the brake piston back, using a pair of slip-joint pliers.





3. Remove the brake caliper and suspend it from the MacPherson strut with a cable tie.
4. Fit the five wheel bolts with four washers on each bolt.





5. Fasten the brake disc measuring tool to the brake caliper mounting lug. Fit the dial gauges.





6. Rotate the brake disc while observing the outboard dial gauge. Zero both gauges when the negative reading obtained on the outboard one is at maximum.
7. Rotate the disc and read the gauges. Note the runout (A) and variation in thickness (B).
8. Remove the dial gauges, brake disc measuring tool and wheel bolts with washers.
9. Fit the brake caliper, apply Loctite 242 part number 74 96 268 to the bolts and tighten with torque wrench.
Tightening torque: 110 Nm (81 ft. lbs.)
10. Fit the wheels and tighten the wheel bolts, using a torque wrench.
Tightening torque: 110 Nm (81 ft. lbs.)
11. Repeat this method of measurement on the other front wheel.
12. When the measurements have been completed, lower the car and depress the brake pedal to press out the brake pads.