This step involves pushing the brake to stop the vehicle. The linkage, consisting of rods, connected to the brake pedal moves the input piston in the master cylinder. The input piston, within the master cylinder, moves the hydraulic brake fluid, which in turn moves the output piston. The output pistons present at all the four wheels, come out of their respective wheel cylinders. The output piston connected to the brake shoes, move the brake shoes against the drum.
Wheel locking The brake shoes rub against the drum causing friction.
The drum connected to the wheel stops, which in turn causes, the wheel to lock and the car to stop. Sometimes, the brake pedal has to be stepped on repeatedly to cause the car to prevent wheel lock. Wheel lock causes the driver to lose control of the car since the wheels cannot be turned. Essentially, the ABS pumps the brakes like a driver would, except at a much faster rate. Activation of ABS ABS uses the ECU to monitor and control the braking system.