The most common handbrake layout used on a four-wheel disc brake system has a small auxiliary drum brake mounted inside the brake disc.
A pair of brake shoes, much the same as those in a normal rear drum brake, are moved outwards by the operation of the handbrake lever. They press against a 'drum' formed by the inner surface of the centre of the brake disc.
The shoes are fitted with a star wheel adjuster to compensate for wear. Once this adjuster has been used, the handbrake cable adjuster can be used to take up any remaining slack.
Most cars are still fitted with drums on the back wheels with the handbrake operating directly o...