Why do brake drums form air holes?

Under normal driving conditions, the brake pads should be checked once every 5000 miles, not only to check the remaining thickness and the wear state of the shoe pads, whether the wear degree on both sides is the same, whether the return position is comfortable and so on, if abnormal conditions are found, it needs to be handled immediately, remember that the brakes must not be replaced until the friction material parts have been worn out; they can be driven at 30 miles/hour speed, after idling. Check the taxiing distance, the average car should not be less than 150 meters. Also check whether the brake of the vehicle is sensitive, to see whether there is a phenomenon of skidding, and whether there is any abnormal brake noise.

The thickness of the new brake pad is generally about 1.5 cm, which will gradually become thinner with the continuous friction in use. When the thickness of the brake pad is only about 1/3 of the original thickness, the owner should increase the frequency of self-inspection and be ready to replace it. Of course, due to hub design reasons, individual models do not have the conditions for naked eye inspection, and need to remove tires to complete.

The brake pad needs to be replaced immediately when the brake is lightly braked and accompanied by the scream of "iron rubbing". Because the limit mark on both sides of the brake pad has directly rubbed the brake disc, proving that the brake pad has exceeded the limit. When this happens, the brake pad should be replaced with the check of the brake disc. When this sound occurs, the brake disc is often damaged.