Patent ID: 7866764

Claim:
A hydraulic control unit for an automotive brake system with a housing ( 49 ) containing a cavity ( 51 ) for a cam shaft of a hydraulic pump ( 35 ) and a low-pressure accumulator ( 54 ), which is at least in part accommodated in the housing ( 49 ) and positioned in a location at a lower height than the cam cavity ( 51 ), the low-pressure accumulator ( 54 ) having an interior space with an accumulator piston ( 59 ) dividing the interior space into an accumulator chamber ( 73 ) and a spring chamber ( 68 ), the piston ( 59 ) being biased toward the accumulator chamber ( 73 ) by means of a spring ( 61 ) arranged in the spring chamber ( 68 ), wherein a drainage bore ( 53 ) connects the cam cavity ( 51 ) with the spring chamber ( 68 ) and the spring chamber ( 68 ) of the low-pressure accumulator ( 54 ) is closed off against the ambience by means of a steel cap ( 63 ) attached to the housing ( 49 ) and wherein the steel cap ( 63 ) comprises a radially extending peripheral rim ( 55 ) located inside the housing ( 49 ), the radially extending peripheral rim ( 55 ) comprising at least one perforation ( 74 ) establishing a hydraulic connection between the drainage bore ( 53 ) and the spring chamber ( 68 ).