During braking, the ABS can quickly determine the locking state of the wheels according to the speed signal from each wheel speed sensor, and close the normally open input solenoid valve on the wheel that starts to lock the wheel, so that the braking force remains unchanged. If it is locked, the normally closed output solenoid valve is opened, and the brake pressure on this wheel will move down rapidly due to the pipeline leading to the brake fluid storage tank, preventing the wheel from being completely locked due to excessive braking force. When the braking state is always at the best point (slip rate S is 20%), the braking effect is the best and the driving is the safest.
The brake fluid in the front cavity of the master cylinder is dynamic pressure brake fluid, which pushes the reaction sleeve to the right, which in turn pushes the booster piston to move the brake pedal push rod to the right. Therefore, when the ABS is working, the driver can feel the vibration of the pedals and hear some noises.