Car or steering wheel shakes / vibrates when braking

A steering wheel that shakes when you hit the brakes can be dangerous. The braking system is a critical safety component of any vehicle and problems with it should be corrected as soon as possible.

A few different issues can cause a shaking car or steering wheel during braking, but almost all of them involve the rotors (brake discs). Regardless of the cause, fixing the problem quickly is important.

How this system works:

Vehicle brakes are available as a disc or drum system. They both use resistance and friction to get the job done. Drum brakes are housed in a round drum rotating with the wheel. In the drum are a set of shoes that are forced against the drum when the brake pedal is pressed.

Disc brakes on the other hand have a rotor that is connected to the wheel. Brake pads, attached to calipers grab the rotor when the brake pedal is depressed, causing friction, which stops the wheel.

Brake pads and shoes will wear down over time and require maintenance and replacement to ensure a safe braking system. New brake pads are 8, 10, or 12 mm thick and they should be replaced when they are worn down to 3mm. Rotors and calipers will also need replacement periodically.

Common reasons for this to happen:

  • Rotor Run Out: This means that the rotors are moving from side to side more than the maximum allowed amount, which is usually .05mm. A common cause of this is a dirty or rusty disc face. It can also be caused by a “thin spot” on the rotor.
  • Uneven Rotors: If the rotors have recently been serviced or new ones have been installed, incorrect tightening can cause the steering wheel to shake when the brakes are applied. Rotors have to be tightened in a specific pattern and to specific torque specifications. If this is not done correctly it can damage the rotors.
  • Warped Rotors: A rotor will warp if exposed to extreme stress for an extended period of time. This can be caused by driving in hilly areas, towing or even cold water hitting a hot rotor. Warped rotors will result in brakes that vibrate, or shake.

How important is this service?

Any issue with the braking system should be addressed immediately. Brakes that constantly cause a vibration or shaking can affect other brake components, which can increase the cost of the repair. In addition, driving with malfunctioning rotors is simply not safe.