Have you ever had your steering wheel shake when you‘re stopping your car? You may think there’s some sort of interconnection between the brake system and the steering column. However, what you’re feeling is not a steering problem but rather a braking issue. 

When brakes are applied, the brake calipers press the brake pads against the rotors that rotate with the wheel. If the rotor is warped, the surfaces are not parallel, the caliper pistons are rapidly pushed in and out as the pads contact high and low spots. These pulsations will cause the entire wheel to vibrate. This vibration, often call 'shimmy,' is transmitted to the brake pedal and steering system components to the steering wheel.

There‘s no doubt the vibration is annoying but is it dangerous? Most modern vehicles are equipped with Anti Lock Braking Systems (ABS). The ABS systemactuates at a high speed or panic stop in an attempt to stop your car from going into an uncontrolled skid. The ABS system accomplishes this by emitting a high speed pulsation to the brake pads. Warped rotors can impact the ABS operation causing an unsafe driving condition. Also severe vibration can damage or cause premature wear to the brake system. The damage can be progressive as the warped rotor wears unevenly as it rubs against the brake pads.

There are several causes for warped rotors. It can result from normal wear of the brake pads. The friction material or the lining of the brake pads consistently grinds away each time you press your brake pedal. Eventually, the friction material is gone and the metal backing of the pad makes contact with the rotor. This creates a metal-on-metal condition that will destroy your rotors. Warping can also occur if the brakes are very hot after a long trip, being applied consistently, or constantly riding the brake pedal. Drive through a puddle of cold water with hot brakes and your rotors will definitely warp. 

Can warped rotors be repaired, or must they be replaced? The answer depends on the amount of rotor run-out -- that is the amount the rotor wobbles. In order to make a rotor “true”, the rotors must literally be shaved by a brake lathe until both sides are smooth.The rotor thickness is measured using specialized precision equipment. Rotors must be discarded and replaced if the thickness falls below a certain level. Your safety is at stake if the thickness of the rotors fall below minimum specifications. Don’t comprimise, replace the rotors.