How Does an Emergency Brake Work?
An emergency brake is a backup braking system designed to function even when there is total brake failure. It works through purely mechanical means, and is independent of the hydraulic system which controls the brakes normally. In addition to being used in emergency situations, an emergency brake is also used as a parking brake, to prevent the car from rolling away, should it slip into gear. Like all parts of the braking system, the emergency brake should be checked regularly to ensure that it is in good working order. To activate the emergency brake, the driver typically pulls up a lever or pushes a pedal in the front of the vehicle. Steel cables attached to the emergency brake run to the rear brakes of the car, which are typically drum brakes. When the cables are tightened, they pull the brake shoes into contact with the drum of the brake, bringing the car to a stop. In the case of disc brakes, the brake cables are attached to a small screw mechanism that pushes a piston into contact
