How to check brake drum?

How to check brake drum?
In normal driving conditions, every 5000 brake pads to check in time, not only to check the status of the remaining thickness and shoe wear, whether the degree of wear and tear on both sides, whether return freely, such as abnormal findings need immediate attention, remember not to brake certain friction materials such as partial are grinding didn't change; Can travel at a speed of 30 li/h, after hanging in neutral, check the taxi distance, the general car should not be less than 150 meters. Check whether the handbrake of the vehicle is sensitive even, see whether have slip car phenomenon, and whether brake has different sound.
The new brake pad thickness is generally about 1.5cm, with the use of continuous friction thickness will gradually become thinner. When the visual observation brake pad thickness has only about 1/3 of the original thickness, the owner will increase the frequency of self-inspection, ready to replace at any time. Of course, due to wheel hub design reasons, some models do not have the condition of visual inspection, need to remove the tire to complete.
The brake pad needs to be replaced immediately when the light touch of the brake is accompanied by the sound of "iron rubbing iron". Because the limit mark on both sides of brake disc has directly rubbed the brake disc, it is proved that brake disc has exceeded the limit. When encountering this kind of situation, the brake disc should cooperate with the inspection of the brake disc when replacing the brake disc. When such sound occurs, the brake disc is often damaged.