Why Does the Car Brake Become Hard?
2 Answers
There are several reasons why a car brake becomes hard: 1. Vacuum-related issues: Factors affecting vacuum include cracks in the atmospheric valve seat, fatigue damage to the diaphragm, cracks or failure of the vacuum valve seat, and failure of the vacuum hose check valve. 2. Free travel issues: If the pedal has no free travel or very little free travel, it may lead to hard braking or excessive pedal force. 3. Jump value and jump point issues: The jump value is not only the main cause of hard braking but also a quantitative indicator of it. The size of the jump value is determined by the height of the jump point, and the initial pedal force sensation is also influenced by the height of the jump point.
Oh no, recently I noticed the brake pedal suddenly became stiff while driving, requiring much more effort to press down, which really startled me. Upon careful consideration, this issue is most likely caused by a problem with the brake assist system, especially a malfunctioning vacuum booster. Normally, it should help make braking easier, but if there's a vacuum leak or blocked lines, all assistance is lost. I've encountered this several times—other causes include insufficient brake fluid or air bubbles in the system, increasing hydraulic pressure, or even seized brake discs, particularly after the car has been parked for a long time. When troubleshooting, I first check if the booster pump hoses are cracked, then listen for any hissing sounds indicating air leaks while braking. If all else fails, I try topping up the brake fluid. Safety comes first—if this happens, it's best not to force driving and head straight to a repair shop to avoid dangerous situations like brake failure at high speeds. I also make it a habit to perform regular maintenance, checking fluid levels every six months to prevent such issues from arising.
