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.