A pump housing, including a pump unit having a collection chamber that receives leaking brake fluid. In the installed position of the pump unit, an outflow bore leads downward from the collection chamber to the ambient air. A body which in one direction allows the outflow of leaking brake fluid and in another direction prevents the entry of splashing water and standing water is press-fitted into the outflow bore. The body comprises a porous sintered metal and on the ambient air side has a flat face end, while its face end toward the collection chamber is embodied in raised fashion.

A hydraulic unit for a hydraulic regulation device, in particular for slip-controlled motor vehicle brake systems, includes several hydraulic, mechanical and/or electrically operable functional elements arranged at an accommodating member, such as accumulation elements, valve elements, pressure-generation and driving elements, and including at least one cavity associated with at least one functional element. Two connecting channels that lead into the atmosphere are provided with closing devices, which hinder the ingress of fluid into the cavity and allow ventilation of the cavity and a discharge of leakage fluid into the atmosphere. The invention permits an automatic bleeding and an automatic removal of leakage fluid independently of the spatial arrangement of the unit.

The invention relates to a piston pump for a slip-controlled hydraulic vehicle brake system. The piston pump has a piston which is driven to execute a stroke motion, and two check valves as an inlet valve and outlet valve for controlling the fluid flow through the piston pump. The outlet valve has a valve closing spring that effects a fast closure of the outlet valve. To enable completely evacuating a positive displacement chamber of the piston pump, the invention includes connecting an evacuation valve, embodied as a springless check valve with a small diameter and with a lightweight valve closing body, hydraulically parallel to the outlet valve.