Abstract: The present invention relates to a position indicator for displaying the position of a piston (3) within a cylinder (1) as part of a piston-and-cylinder assembly (1, 3) in a brake system. The provision of a Hall element for a hydraulic generating cylinder is known in the art, with the Hall sensor mounted on the cylinder and a ring magnet mounted on the piston. An object of the invention is to describe a position indicator for a brake system, which has a simple construction and is able to provide signals relating to the position of the brake pedal relatively rapidly. This object is achieved because a Hall element of a Hall sensor (12) is placed in the cylinder wall (1) of the master cylinder, and because a magnetic zone (9) is arranged in the piston-and-cylinder assembly so that the Hall element responds to the piston movement within the cylinder.