A piston pump includes a perforated disk as a throttle, in a central hole of which an outlet valve is arranged and its inner edge is fixed externally on a cylinder sleeve base of the piston pump and an outer edge of which lies with prestress on an annular support. Brake fluid displaced out of the piston pump lifts the perforated disk-shaped throttle off from the annular support, with which a dynamic throttle is formed. A throttle channel which negotiates the annular support in the perforated disk-shaped throttle also enables a throughflow in the case of a throttle lying on the annular support.