Reasons Why the Brake Pedal of an Automatic Transmission Car Won't Depress
2 Answers
Reasons why the brake pedal of an automatic transmission car won't depress: 1. The car's vacuum booster pump is leaking or malfunctioning. 2. The brake was pressed after the engine was turned off. 3. If the automatic transmission car won't start and the brake pedal won't depress, it may be due to a lack of vacuum assistance, requiring more force. If this doesn't work, the issue might be with the switch, and it is recommended to replace it. 4. The most likely reason for the brake pedal not depressing and the car not starting is that the brake was pressed multiple times after the last engine shutdown. Solution: In this case, apply more force to depress the brake pedal, then press the ignition switch to start the engine. After the engine starts, you will noticeably feel the brake pedal sinking, as the engine intake pipe has formed a vacuum, and the vacuum booster pump begins to provide assistance.
A few days ago, my car's brake pedal suddenly became hard to press, which gave me quite a scare. Fortunately, I was driving slowly in the city at the time, so I quickly pulled the handbrake and pulled over. The mechanic later checked and said the vacuum booster might be faulty. This component relies on engine vacuum to provide assistive force. If the engine isn't running or is frequently turned off, the vacuum pressure becomes insufficient, making the brake pedal as hard as a rock and impossible to depress. I also learned that insufficient brake fluid or leaks in the system can prevent the hydraulic system from building pressure, causing brake failure. When driving daily, avoid frequently turning off the engine to save fuel, and during regular maintenance, check the brake fluid level and color—it should normally be a clear yellow or light yellow. If you encounter a similar situation, don't hesitate—immediately turn on the hazard lights and slowly pull over to avoid causing an accident. In short, brake issues are matters of life and safety, and minor problems should never be ignored.
