Why is the brake pedal stiff?
2 Answers
Vacuum valve seat has cracks or is already ineffective, and the one-way valve of the vacuum hose is malfunctioning. Below is an introduction related to brakes: 1. Terminology explanation: A mechanical braking device that can slow down the speed of a vehicle, also known as a decelerator. The car's brake pedal is located under the steering wheel. Pressing the brake pedal causes the brake lever linkage to be pressurized and transmitted to the brake shoes on the brake drum, clamping the brake disc, thereby slowing down or stopping the vehicle. 2. Brake function: The principle of braking is to convert the vehicle's kinetic energy into heat energy and dissipate it. The kinetic energy comes from the power provided by the engine, which requires fuel combustion to perform work. In other words, every time you press the brake, it means a bit of gasoline is wasted.
When I first started driving, I also experienced the issue of the brake pedal being hard to press. Later, a mechanic told me that the most likely cause was a problem with the vacuum booster. That device uses engine suction to create a vacuum, helping you save effort when braking. If its hose is leaking or the one-way valve is faulty, the brake pedal will become as hard as a rock after a couple of presses when the engine is off. There’s an even scarier situation where the rubber cup inside the brake master cylinder gets stuck. In this case, no matter how hard you press the pedal, the car won’t stop. Once, my car had this issue, and it turned out to be caused by dirt getting in during maintenance. I suggest you test it immediately: after turning off the engine, press the brake pedal several times. If the pedal rises higher but remains very hard, it’s likely a vacuum pump leak. If it’s completely unmovable, the master cylinder might be done for.
