Method for operating a car brake unit

A method for controlling a hydraulic lift brake having a hydraulic actuator with required for applying the braking force-biased piston rod has a by a main spring unit in the closing direction, which is connected to a piston which, depending on which hydraulic pressure to it is applied, compensates for the force of the main spring unit completely or partially, with the resulting force with which the actuated from the piston rod brake pad is pressed against the rail, is regulated by means of a speed and / or torque-controlled and / or multi-quadrant operation up engine or controlled , the first alternative, depending on the current need, either a hydraulic pump so drives that the hydraulic pump pumps hydraulic fluid, and thereby the resultant force acting on the brake lining is reduced or a hydraulic pump so slows brake motor or a generator that over flows back flow of hydraulic fluid and thereby is increased, the resulting force acting on the brake pad or of either a hydraulic pump as drive in the second alternative - contrary to its actual conveying direction of the hydraulic fluid as a hydraulic motor-driven hydraulic pump, contrary to their conveying direction a - preferably adjustable or controllable that the hydraulic pump either hydraulic fluid promotes and thus the resulting force acting on the brake pad, reduces or that via the hydraulic pump, contrary to its direction of conveyance flows back a leakage current and thereby is increased, the resulting force acting on the brake pad.