Uneven brake discs
The usual cause is front brake discs (rotors) with uneven thickness or deposits, often after heavy braking or a hot stop. You feel it as a pulsing pedal and a shaking wheel.
Shake at the rear
If you feel it more through the seat than the wheel, the rear brakes may be the cause.
Other causes
Loose or worn suspension and steering parts, or wheel nuts not tightened evenly, can also cause shaking that shows up when braking.
What to tell the mechanic
At what speed it happens, whether it is through the wheel or the seat, and when the brakes were last done.
Safe to drive?
Mild shudder with a firm pedal: book in soon. Grinding, a soft pedal or the car pulling hard: stop driving and get it checked.
General guidance only, not a diagnosis. If in doubt, do not drive it and have it inspected. In an emergency, call 111.
Who can help
Get quotes for brake repairs near you
Questions
Can discs be machined?
Sometimes, if they are thick enough. Often replacement is better value. Ask for both options in the quote.
Do I need new pads too?
Usually pads are replaced with new discs so they bed in evenly.