How to repair the brake cylinder not returning

There are brake master cylinder and brake cylinder in the brake system. In simple terms, the master cylinder is where the brake oil is stored, and has an oil outlet and an oil inlet. When we step on the brake pedal, the oil in the brake master cylinder It will flow to the brake cylinder through the pipeline. When the cylinder is under pressure, it will push the brake pads to make the brake pads rub against the brake drum, so as to achieve the purpose of braking.
The brake cylinder does not return, in short, even if you don't step on the brake pedal, you still obviously feel the resistance of the car. If the brake oil is not changed for a long time, which causes the internal rust of the brake cylinder, it can be repaired by sanding and applying butter; if the cylinder itself is faulty, it is likely to be replaced directly.
chinafuao.net