
If the automatic transmission car won't start and the brake pedal can't be pressed down, it's likely due to lack of vacuum boost, which may require more force. If that doesn't work, there might be an issue with the switch, and replacement is recommended. Here are the specific reasons why the brake pedal can't be pressed down: 1. The car's vacuum booster pump is leaking or malfunctioning. It's important to know that 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 difficult to press down. 2. The brake pedal was pressed after the engine was 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 on the remaining vacuum boost, which typically depletes after a few presses. However, this condition will recover after restarting and is not a malfunction.


