Having a car vibrate when the brakes are applied is a common problem for many car owners. Most of the time, this is a result of the front brakes being worn out, which is usually due to warping.
Warping of older brakes usually leads to uneven force distribution around the brake plates when the brakes are applied. This results in vibration of the wheel, which is then transmitted to the rest of the car. The severity of the vibration depends on the severity of the brake pad warping. Pads that are severely worn out tend to make the car vibrate when brakes are applied when driving slowly, but less severe warping is only noticeable when the brakes are applied while the car is moving fast. This in itself is not a major problem, so one can continue using the car for some time once they notice the problem. However, it is important to have the car inspected soon, since the problem could rapidly become worse and cause more noticeable effects. Neglecting a brake problem might result in damage to other parts of the car, such as the tires, which would require more money to repair later on. As brake problems progress, they also make use of a car increasingly unsafe.