What Causes the Brakes to Suddenly Become Hard and Unresponsive While Driving?

1 Answers
MacPaisley
07/29/25 8:17am
99% of passenger cars are equipped with vacuum-assisted brake systems, where the vacuum is generated by the engine. The following situations may occur: 1. Engine Stalling: If the engine stalls, it cannot generate vacuum. After pressing the brake pedal once, the vacuum is depleted, making the pedal harder to press afterward. 2. Frequent Braking: Rapid and continuous braking can cause the engine's vacuum supply rate to lag behind the vacuum consumption rate. 3. High Altitude Areas: In high-altitude regions, the vacuum level is naturally lower, meaning the vacuum pump stores less vacuum. The first brake application might feel normal, but subsequent continuous braking may give a sensation of insufficient braking power. Therefore, it is recommended to use the gear shift mechanism more often for braking when going downhill.
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