Why can't the brake pedal be pressed down when starting the car?
1 Answers
The reasons why the brake pedal cannot be pressed down when starting the car include a faulty vacuum booster pump, stepping on the brake after the engine is turned off, and lack of maintenance of the brake system. Faulty vacuum booster pump: The force applied to the brake pedal is amplified by the brake booster pump. If it fails, the brake loses its main power source, making it impossible to press down. In this case, immediate repair or replacement is required. Stepping on the brake after the engine is turned off: This is also related to the brake booster pump. The brake booster pump only continuously generates vacuum when the engine is running. When the engine is off, it relies solely on the residual vacuum, which typically allows only a few presses before becoming ineffective. In this situation, a short wait is sufficient. Lack of maintenance of the brake system: Too much debris in the master cylinder, poor sealing, failure of the vacuum booster pump, dirty brake fluid or mixing different types of brake fluid causing vapor lock when heated, leakage in the master or wheel cylinders, or leaks in the air reservoir or pipe connections. In this case, maintenance at a 4S shop is necessary.