Submersible cover for a low pressure accumulator

An anti-lock brake system comprising:

• an electronic controller;
• a wheel brake;
• a hydraulic pump operated by an electrical motor electrical motor with the electrical motor being electrically connected to the electronic controller;
• a relief line disposed between and fluidly connecting the wheel brake and an inlet port of the hydraulic pump;
• a solenoid operated relief valve electrically connected to the electronic controller and disposed in the relief line and the relief valve blocking flow from the wheel brake to the hydraulic pump when in a closed position and the valve operably opening responsive to an electrical signal from the electronic controller thereby enabling a dumping of brake fluid from the brake;
• and
• a fluid accumulator receiving hydraulic fluid from the brake when the relief valve is open and the hydraulic pump is not displacing fluid, the accumulator including
• a valve body portion defining an accumulator chamber having a fluid inlet at a first end of the chamber in fluid communication with the relief line and the chamber being open to atmosphere at a second end of the chamber,
• an accumulator piston slidably disposed within the accumulator chamber separating the first end of the chamber from the second end of the chamber and having hydraulic fluid disposed on a side facing the first end,
• a spring disposed between the piston and the second end of the chamber biasing the piston toward the first end, and
• a cover closing the second end of the chamber and having a semi-permeable structure configured to block water molecules and communicate air.