Abstract: A breathable low pressure accumulator includes a housing with a cylindrical bore formed therein. A piston slides within the bore and includes an elastic piston head. A biasing member urges the piston towards a first end of the bore. At least one passage communicates between an exterior of the housing and a volume that is enclosed by the bore and the elastic piston head. The elastic piston head is formed of rubber. The elastic piston head is molded into the piston.

Abstract: A breathable low pressure accumulator includes a housing with a cylindrical bore formed therein. A piston slides within the bore and includes an elastic piston head. A biasing member urges the piston towards a first end of the bore. At least one passage communicates between an exterior of the housing and a volume that is enclosed by the bore and the elastic piston head. The elastic piston head is formed of rubber. The elastic piston head is molded into the piston.

Abstract: A hydraulic control unit of an electronically controlled hydraulic brake system has a housing (49) accommodating a pump (35) and at least one low-pressure accumulator. The low-pressure accumulator is positioned in a location at a lower height than the cam cavity (51) of the pump (35), and a drainage bore (53) connects the cam cavity (51) with the spring chamber (68) of at least one of the low-pressure accumulators. This allows the drainage of brake fluid from the cam cavity (51) into the spring chamber (68) solely by way of gravity. Thus this measure eliminates the risk of damage to the pump motor in the event that ambient water penetrates the cam cavity (51), which might flush brake fluid from the cam cavity 51 into the housing (49) of the pump motor.