What causes unevenness in the brake pads?

If it is a car that has not changed its brake pads, it means that your brake pads need to be replaced. In this case, the grinding pattern is relatively shallow. If you have just changed the brake pads, it is normal to have a slight sound. Because the old brake pads will wear the brake disc because of a variety of factors such as intersection and texture, and this wear is still uneven will leave a circle of uneven concentric circles on the brake disc, and when you replace the new brake pad, the texture of the new brake pad and the texture of the old brake pad is still slightly different, and because the surface of the new brake pad is flat, the surface of the brake pad will be ground during the production process, then the uneven brake disc is worn, and there will be a little sound at this time.