The brake pad thickness can be viewed as follows:

1. The standard is generally about 1.5cm. With the brake operation during the use of the car, the friction will reduce the thickness. Generally, the critical point of brake pad thickness is about two or three millimeters. If the brake pad thickness is less than 3 millimeters, it must be replaced.

2. It can be viewed with naked eyes. Some brake pads can be seen through the gap of the wheel hub. If the brake pads have worn to one third of the standard thickness, it is recommended to replace them. However, some models are also due to the wheel hub design. It is difficult to check the brake pad thickness without removing the tires, which is troublesome.

3. For some models, when the brake pads are too thin, the position of the instrument hand brake light will be prompted. There is also a tool to check the brake pad thickness, which can better check the brake pad thickness.

4. It can also be judged by feeling that if the brake is hard, it may be that the brake pads are not thick enough and the friction is not enough, and they need to be replaced in time, otherwise an accident will occur. The replacement cycle of the brake pads should be determined according to the vehicle environment and driving habits. Generally, they should be replaced after driving about 40,000 km. When it is found that the brake pads are thin or hard to brake by visual inspection, it is also recommended to replace them in time. It is better to go to a professional repair shop for inspection and replacement.