What Causes Brake Failure?
2 Answers
Reasons for brake failure: 1. The vehicle's vacuum booster pump is leaking or malfunctioning. The force applied to the brake pedal is amplified by the brake booster pump. If it fails, it becomes difficult to depress the pedal; 2. The brake was pressed after the engine was turned off. This is also related to the brake booster pump, which continuously generates vacuum only when the engine is running. However, in this case, the brake will return to normal after restarting the engine, and it is not a malfunction. If you encounter brake failure while driving, stay calm. Press the brake pedal multiple times to increase the chance of restoring braking force. Additionally, turn on the hazard lights to alert surrounding vehicles. If necessary, slowly engage the handbrake to gradually increase braking force.
The brake pedal being hard to press can be caused by several situations. For example, a faulty brake booster, especially a broken vacuum booster, can make the pedal as hard as a rock, requiring great effort but with little deceleration effect. It could also be due to brake fluid leakage or insufficient fluid, or air entering the pipelines, causing an imbalance in the braking system pressure. The last time I encountered this issue was during a long-distance drive. After inspection, it turned out to be a ruptured booster pump hose, and replacing the part solved the problem. In such cases, it's best not to force driving. Instead, find a safe place to stop and call for roadside assistance, as it concerns both your safety and that of others.