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:
If Steam Is Coming from the Engine Compartment
Warning
Steam from an overheated engine can burn you badly, even if you just open
the hood. Stay away from the engine if you see or hear steam coming from it. Just
turn it off and get everyone away from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before yo ...
Automatic Transmission Flex Plate Removal
Special Tools
EN-652 Automatic Transmission Flex Plate Holder
For equivalent regional tools, refer to Special Tools.
Install the EN-652 holder (1) to hold the automatic transmission
flex plate (2).
Loosen the 6 automatic transmission flex plate bolts.
Remov ...
Valve Stem Oil Seal and Valve Spring Replacement
Special Tools
207649 Rod Hairpin Clips
547324 Flange Screws
EN-840 Pliers / Remover
EN-958 Installer
EN-45059 Angle Meter
EN-50717 Kit
J-43649?E Rods
For equivalent regional tools, refer to Special Tools.
Removal Procedure
Remove the spark plugs. Refer to Spark ...
0.0077