Abstract: An electronically controllable anti-lock brake actuation system for automotive vehicles, including a pedal actuated dual-circuit master brake cylinder, and braking pressure generators actuatable by an electronic control unit. Each of the braking pressure generators has a piston slidable in a cylinder bore from an initial position, each piston separating a first working chamber, to which each one wheel brake of the vehicle is connected directly and the master cylinder is connected by way of a closable hydraulic connection, from a second working chamber and is connected to the master cylinder where the stepped piston is operable to achieve a braking pressure generation or boosting.