The brake is a commonly used braking device on mechanical equipment, and it is also used on some power-operated equipment, such as automobiles and cranes. Take the bicycle, for example, the new car will be more comfortable to ride, but as the service life increases, the brakes will fail, or the brakes will not hold. Imagine the danger of not being able to brake for a bicycle, so for a faster car or mechanical equipment, the danger has increased a lot. Therefore, we need to find out the cause of the brake failure and avoid accidents. First of all, let's understand the several types of failure of the lower brake: 1. Stop when the power is cut off, the gate automatically drops slowly or the hook quickly falls, and the brake fails seriously; 2. When the power is applied, the brake shoe does not loosen or delays the brake release ; 3. There is vibration and noise when the electromagnetic circuit is attracted when the brake is working. The causes of brake failure are divided into mechanical and electrical reasons. Mechanical failures include: failure to operate or open the brake when the brake is energized, failure to hold the brake, failure to hold the brake (slow braking), wear or even burning of brake pads, and large vibrations.