Why does my steering wheel shake when I brake?
A steering wheel that shakes, or a brake pedal that pulses, when you slow down is usually caused by front rotors that have worn unevenly, often called warped rotors. It's most noticeable braking from highway speed. It's not usually an emergency, but it gets worse over time and lengthens stopping distance, so have the rotors checked soon.
Why it happens
- Uneven pad deposits after hard stops, especially holding the brakes at a stop when they're hot
- Rotor thickness variation from wear, rust or a rotor that has run too thin
- Wheel lug nuts tightened unevenly, often with an impact gun instead of a torque wrench
- A sticking caliper that drags on one side
- Worn suspension parts that let the wheel shake when braking forces load them
How it's fixed
We measure rotor thickness and runout, check the calipers and slide pins, and look at the suspension for play. The usual fix is new or resurfaced rotors with fresh pads, properly bedded in, and lug nuts torqued to spec.
If the shake happens while cruising and not only when braking, the cause is more likely tires or balance. Highway vibration
More questions
Are my rotors actually warped?
Usually not literally. More often, pad material has deposited unevenly or the rotor has worn to uneven thickness. The effect is the same: the pads grab and release as the rotor turns.
Can rotors be resurfaced to fix the shake?
If they're thick enough after machining, yes. If they'd end up below the minimum thickness stamped on the rotor, they need replacing.
The shake is in my seat, not the steering wheel. Why?
A vibration felt through the seat or pedal under braking usually points to the rear rotors or drums.