Controllable coolant pump, constructed as a controllable axial pump, with a pump housing with a flow intake opening and a flow discharge opening with a pump shaft placed on/in the pump housing and arranged in a rotational manner by using a pump bearing and connected in a fixed manner relative to the rotation of the belt driven pulley and with an axial paddle wheel arranged on this pump shaft, characterized by the fact - that a guide wheel is arranged a torque-proof manner in the pump housing where a bearing seat is located, where a bearing is arranged in which where the pump shaft is seated with the pump shaft end in a bearing opposite to the belt driven pulley at a predetermined distance from this bearing adjacent to the direction of the flow intake opening, the axial paddle wheel is arranged in a torque-proof manner on the pump shaft provided with a preliminary guide wheel arranged in a torque-proof manner in the pump housing adjacent to a pump shaft passage opening with a preliminary guide wheel arranged in a torque-proof manner in the pump housing with a directional intake cone arranged at the guide wheel in the direction of the flow discharge opening, with directional discharge cone and an annular rib opposite to the bearing seat, and - that a sliding valve working compartment is arranged in the pump housing penetrated by the directional discharge cone of the guide wheel where a piston rod guide is located with an actuator mounting flange and is arranged in the direction of the flow opposite to the bearing position of the pump bearing in the pump housing, a moveable piston rod projecting into the pump housing is mounted in this piston rod guide acting on the end of the piston rod outside of the pump housing, a linear movement of the piston rod arranged at the actuator mounting flange of the pump housing, which acts with a reset mechanism even when regulation of the provided actuator fails, a linearly moveable axial valve provided in the sliding valve working compartment and at the end of the piston rod is fastened and located inside the pump housing with an outlet guiding edge, an outlet opening and also a radial groove to provide an operative sealing connection with the annular rib, this actively controls the coolant supply so that there is "zero leakage", and - that an intake flange and a drainage flange are arranged at the pump housing which are arranged "at an angle" to the sliding valve working compartment arranged in the pump housing. - that a guide wheel is arranged a torque-proof manner in the pump housing where a bearing seat is located, where a bearing is arranged in which where the pump shaft is seated with the pump shaft end in a bearing opposite to the belt driven pulley at a predetermined distance from this bearing adjacent to the direction of the flow intake opening, the axial paddle wheel is arranged in a torque-proof manner on the pump shaft provided with a preliminary guide wheel arranged in a torque-proof manner in the pump housing adjacent to a pump shaft passage opening with a preliminary guide wheel arranged in a torque-proof manner in the pump housing with a directional intake cone arranged at the guide wheel in the direction of the flow discharge opening, with directional discharge cone and an annular rib opposite to the bearing seat, and - that a sliding valve working compartment is arranged in the pump housing penetrated by the directional discharge cone of the guide wheel where a piston rod guide is located with an actuator mounting flange and is arranged in the direction of the flow opposite to the bearing position of the pump bearing in the pump housing, a moveable piston rod projecting into the pump housing is mounted in this piston rod guide acting on the end of the piston rod outside of the pump housing, a linear movement of the piston rod arranged at the actuator mounting flange of the pump housing, which acts with a reset mechanism even when regulation of the provided actuator fails, a linearly moveable axial valve provided in the sliding valve working compartment and at the end of the piston rod is fastened and located inside the pump housing with an outlet guiding edge, an outlet opening and also a radial groove to provide an operative sealing connection with the annular rib, this actively controls the coolant supply so that there is "zero leakage", and - that an intake flange and a drainage flange are arranged at the pump housing which are arranged "at an angle" to the sliding valve working compartment arranged in the pump housing.