Pump for a high-pressure cleaning device

The invention relates to a pump for a high-pressure cleaning unit for delivering a cleaning liquid having at least one pump chamber, into which at least one piston which can be moved to and fro dips and which is connected to a suction line via at least one inlet valve and to a pressure line via at least one outlet valve, and having a bypass line which leads from the pressure line to the suction line and in which a crossflow valve is arranged, the valve body of which is connected to a control piston which is held displaceably in a control chamber with the interposition of a sealing element and displaces the valve body into a closed position or an open position as a function of the flow rate of the cleaning liquid in the pressure line. In order to develop the pump in such a way that it can be produced in a manner which is less expensive and less susceptible to faults, it is proposed according to the invention that a sliding element which bears sealingly against the wall of the control chamber is arranged in the