Why do traffic lights shake when you step on the brakes?

The surface of the brake disc is uneven and the radial runout is too large. When braking, the contact between the brake pad and the brake disc is loose and tight, and the braking force is large and small, causing the car body to vibrate.

There is a big deviation in the wheel alignment data, especially when the front wheel alignment angle is inaccurate, the toe-in is too large, and the tire pressure is too high or too low. The higher the vehicle speed, the more severe the body shake, and the tire pressure is too low, and the body will feel confused and wandering.

Precautions for braking

The common brake system is abnormal brake sound, which has been encountered by many car owners. Abnormal brake noise generally means that when the vehicle steps on the brake while driving, the brake system will make a sharp metal friction sound, which often occurs after rain.

If this happens, it is mostly because the brake pads are thinner, the back plate grinds the brake disc, the brake pads are hard (poor quality), and there are foreign objects in the brake pads, which will lead to abnormal noise. Therefore, when abnormal braking noise occurs, the brake pad thickness should be checked first. If the thickness is ok, a few feet of sudden braking may alleviate the abnormal noise problem.