A device for monitoring the position and movement of a brake pedal for motor vehicles, including a power assist brake actuating unit. The brake actuating unit having a master cylinder fastened to the brake power assist unit, a housing and at least one piston displaceable in a linear manner in the master cylinder, and a position indicator for monitoring the position of the brake pedal. The position indicator transmits signals to a sensor element connected to an electronic control unit. The position indicator is provided on a support coupled to the movement of the control valve housing or to the movable wall that is supported by the control valve housing. The support is guided in a housing of a sensor element, and the housing of the sensor element penetrates in a vacuum-tight manner the power assist unit housing and the housing of the master cylinder having a first housing section.