Abstract: A piston pump for a hydraulic brake system for a vehicle with a slip control system. For economical production, the piston pump includes a piston as a composites part with a core of steel that is surrounded by a lubricant jacket of plastic. By way of example, the lubricant jacket is applied to the core by spray-coating, or is pressed onto the core or slipped onto the core. The lubricant jacket economizes by dispensing with expensive post-machining of the piston surface by grinding, for instance, and improves the sliding properties of the piston.

Abstract: A piston pump which is intended in particular for a vehicle hydraulic, slip-controlled brake system. To reduce idle volume in the piston pump, a positive-displacement body is mounted on the piston by means of a retaining part. The displacement body protrudes into an interior of a valve closing spring, embodied as a helical spring, of an inlet valve integrated with the piston. The embodiment of the valve closing spring and of a piston restoring spring with a rectangular coil cross section also contributes to reducing the idle volume of the piston pump. Reducing the idle volume increases the efficiency of the piston pump.