What are the reasons for the brake becoming hard and failing when reversing?

[McLogan]

When reversing, the brake becoming hard and failing may be due to air leakage or malfunction of the brake booster pump. Here are the relevant details: Introduction: If this situation occurs before driving the car, it is recommended that the driver avoid operating the vehicle. Additional Information: The operation of the car's brake pedal can be categorized into slow braking (i.e., anticipatory braking), emergency braking, combined braking, and intermittent braking. Generally, avoid stomping on the brake pedal all at once. Instead, press the brake pedal first, adjusting the pressure (i.e., increasing the force) according to the need. When the vehicle is moving at a higher speed, apply the pressure quickly and firmly; when the vehicle is moving slowly, apply the pressure gently and steadily. Then, adjust the pressure further based on different situations, either increasing or decreasing it as needed.