The brakes were tight before the car started. What happened?

1, cause of failure: related to stepping on the brake before flameout; The braking system of an automobile can only play its greatest role when the engine is working, and the brake booster pump is the driving force of vehicle braking, and the force of stepping on the pedal is amplified through it.

When the engine is turned off, the brake booster pump will stop. Generally, stepping on the brake pedal for three times will use up its remaining vacuum force, so it is actually lacking its help to think that the brake is hard.

Solution: In this case, just restart the engine, and then try to press the brake pedal hard to restart. After the engine works, the brake booster pump can work again and the natural brake pedal will return to normal.

2. Cause of failure: air leakage or failure of automobile brake booster pump. If you don't step on the brake pedal after the car is turned off, or you find it difficult to step on the brake pedal while driving, it is probably caused by the failure of the brake booster pump. It may be caused by air leakage or blockage of the vacuum tube of the brake booster pump.

Solution: in view of this situation, if this situation is found before driving, it is best not to continue driving on the safe side and send it directly to the repair shop for maintenance; If you find it while driving, don't panic. The first thing to do is to slow down and stop. You can try stepping on the pedal several times to see if you can resume braking. When you step hard, you can generally exert your braking force.

Extended data

Causes of brake failure

First of all, the brake system lacks necessary maintenance. There are too many impurities in the brake master cylinder, the seal is not tight, the vacuum booster pump fails, the brake oil is too dirty, or there is air resistance after several brake oils are mixed and heated, the brake master cylinder or the slave cylinder leaks oil, and the air storage tank or pipeline interface leaks air;

Second, due to improper operation, parts fail, such as friction and heating of brake pads, carbonization of brake hub and complete failure of downhill braking function for a long time;

Thirdly, due to serious overload, under the action of gravity acceleration, the inertia of vehicle motion increases, which directly leads to brake failure.