What Causes the Brake Pedal to Be Hard to Press and the Car Unable to Start?
2 Answers
Here are the reasons why the brake pedal is hard to press and the car cannot start: 1. The car'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, the brake loses its assist, making it difficult to press. 2. Pressing the brake after the engine is turned off is 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 on the remaining vacuum assist, which will restore after restarting and is not a malfunction. 3. In driving, to prevent unexpected situations like sudden movement or rolling when starting the car, automatic transmission models are designed to require pressing the brake to start. If the brake is not pressed, the car cannot successfully start. Additionally, the gear must be in P (Park) or N (Neutral) when starting an automatic transmission car. If starting in N without the handbrake engaged, the car may roll, so the "press brake to start" design is entirely for safety considerations.
That day when I went out driving, as soon as I stepped on the brake, it felt stiff and unresponsive, and the car just wouldn't start no matter what, which really frustrated me. After checking, it might be an issue with the brake vacuum booster pump. This component relies on engine vacuum to function; if there's a leak in the pipeline or the pump itself is damaged, the brake becomes particularly heavy. Another possibility is insufficient brake fluid, causing the oil pressure to be too low to press down. Additionally, modern cars require you to press the brake to ignite; if the brake switch malfunctions or there's a short circuit in the wiring, the system mistakenly thinks the brake isn't pressed, hence the car won't start. A dead battery could also lead to the booster pump failing. This issue is quite dangerous. If encountered, first check the brake fluid level and the fuse box. If that doesn't help, quickly head to a repair shop for inspection—don't force driving to avoid accidents. Regular maintenance, such as changing the brake fluid and servicing the vacuum system, can help prevent this.