Volt

Brake Disc/Drum Balance Inspection

Danger: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.

1. Support the vehicle drive axle on a suitable hoist. Refer to Lifting and Jacking the Vehicle .
2. Remove the tyre and wheel assemblies from the drive shaft. Refer to Tyre and Wheel Removal and Installation .

Warning: Refer to Work Stall Test Warning in the Preface section.

3. Reinstall the wheel nuts in order to retain the brake discs.
4. Run the vehicle at the concern speed while inspecting for the presence of the vibration.

Caution: Do not depress the brake pedal with the brake discs and/or the brake drums removed, or with the brake callipers repositioned away from the brake discs, or damage to the brake system may result.

5. If the vibration is still present, remove the discs from the drive shaft, then run the vehicle back to the concern speed.
6. If the vibration is eliminated when the brake discs are removed from the drive shaft, repeat the test with one disc installed at a time. Replace the disc that is causing or contributing to the vibration concern.



7. If a brake disc was replaced as a result of following the previous steps, or if necessary to confirm the results obtained during the previous steps, and/or to check the non-drive shaft components, perform the following:

7.1.	Mount the brake disc/drum on a balancer in the same manner as a tyre and wheel assembly.

Note: Check brake rotors/drums for static imbalance only; ignore the dynamic imbalance readings.

7.2.	Inspect the disc/drum for static imbalance.

There is not a set tolerance for brake disc/drum static imbalance. However, any brake disc/drum measured in this same manner which is over 21 g (¾ oz) may have the potential to cause or contribute to a vibration. Discs/drums suspected of causing or contributing to a vibration should be replaced. Any disc/drum that is replaced should be checked for imbalance in the same manner.