Chevrolet Sonic Repair Manual: Brake Rotor Thickness Variation Measurement
Warning:
Refer to Brake Dust Warning.
Note:
Any disc brake rotor that exhibits thickness variation exceeding the maximum acceptable level must be refinished or replaced. Thickness variation exceeding the maximum acceptable level can cause brake pulsation.
- If the inboard friction surface of the brake rotor is not accessible, reposition and support the caliper with the brake pads. Refer to Front Disc Brake Pads Replacement.
- Clean the friction surfaces of the brake rotor with denatured alcohol, or an equivalent approved brake cleaner.
- Using a micrometer (1) calibrated in thousandths-of-a-millimeter, or ten-thousandths-of-an-inch,
measure and record the thickness of the brake rotor at 4 or more points, evenly
spaced around the brake rotor.
Make sure that the measurements are only taken within the friction surfaces and that the micrometer is positioned the same distance from the outer edge of the brake rotor, about 13 mm (1/2 in), for each measurement.
- Calculate the difference between the highest and lowest thickness measurements recorded to obtain the amount of thickness variation.
- Compare the thickness variation measurement to the following specification:
Specification
- J93, J94: 0.02 mm (0.0008 in)
- JPW, J97: 0.02 mm (0.0008 in)
- J93, J94: 0.02 mm (0.0008 in)
- If the brake rotor thickness variation measurement exceeds the specification, the brake rotor requires refinishing or replacement.
Note:
Whenever a brake rotor is refinished or replaced, the assembled lateral runout (LRO) of the brake rotor must be measured to make sure optimum performance of the disc brakes.
Brake Rotor Thickness Measurement
Warning: Refer to Brake Dust Warning.
If the inboard friction surface of the brake rotor is not accessible, reposition
and support the caliper with the brake pads. Refer to Front Disc Bra ...
Brake Rotor/Drum Balance Inspection
Support the vehicle drive axle on a suitable hoist. Refer to Lifting and
Jacking the Vehicle.
Remove the tire and wheel assemblies from the drive axle. Refer to Tire
and Wheel Removal and ...
Other materials:
Parking Brake
To set the parking brake, hold the brake pedal down and pull up on the parking
brake lever. If the ignition is on, the brake system warning light will come on.
See Brake System Warning Light.
To release the parking brake, hold the brake pedal down. Pull the parking brake
lever up until you ...
Front Side Door Check Link Replacement
iii!
Front Side Door Check Link Replacement
Callout
Component Name
Preliminary Procedure
Remove the front side door trim panel. Refer to Front Side Door Trim
Replacement.
1
Front Side Door Check ...
Engine Control Module Replacement
Engine Control Module Replacement
Callout
Component Name
Note: If the ECM is to be replaced, the ECM must be RESET
(prepared for removal) prior to removal from the vehicle. Failing to
reset the ECM will result in the ...
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