1.The brake pedal does not return
This problem is caused by oil leakage in the master cylinder or the sub-cylinder, or the pedal sinking due to the failure of the master cylinder and the sub-cylinder. In addition, the bearing of a certain shaft may be worn, lack of oil, and damaged. Damage to the bearings can cause inconsistencies throughout the car. The brake pads appear in an improper position, causing the brake pedal not to return.
2.Brake becomes hard or soft
It is normal for the brake pedal to be hard when the vehicle is stopped, because the vacuum booster pump is not working yet. If the pedals are still hard after the vehicle is started, there is probably a leak in the vacuum tube or the vacuum pump is broken. If the brakes become soft during driving, it is a very dangerous sign! This means that there is air in the brake oil pipeline, or the brake fluid leaks, you need to stop immediately and enter the store for repair.
3.The steering wheel is deflected to one side when braking
When braking, it is difficult to feel the partial braking due to the fast rotation of the brake disc, but this difference becomes more apparent when the vehicle is about to stop. The wheel on the fast side stops first, and the steering wheel will deflect. This is because the left and right sub-pumps of the braking system have an uneven effect on the brake pads. In this case, the sub-pumps must be replaced in time.