Coolant ventilation system

A cover assembly for a cooling fluid reservoir, said cover assembly comprising:

• a body including an annular mounting portion:
• at least one vent valve being positioned in the body and operating to vent the reservoir through a vent channel;
• and
• a fill cap threaded onto the mounting portion, said fill cap including a cylindrical portion extending into the mounting portion and including an annular channel, said cylindrical portion including a flat seal that seals a fill tube when the fill cap is completely closed and a sealing ring positioned within the annular channel, wherein the sealing ring seals the fill tube when the fill cap is partially removed so that reservoir is allowed to vent to the vent channel when the fill cap is partially removed.

A multi-functional unit for a coolant reservoir, said coolant reservoir storing a cooling fluid and including a gas region therein, said coolant reservoir including a fill port in fluid communication with the inside of the coolant reservoir, said multi-functional unit mounted to the coolant reservoir and covering the fill port, said multi-functional unit comprising:

• a vent line;
• a fill line;
• a first vent valve in fluid communication with the fill port and the vent line, said first vent valve automatically venting the gas region if the pressure in the gas region exceeds a first predetermined pressure;
• a check valve in fluid communication with the vent line and the fill port, said check valve allowing air to enter the gas region if the pressure within the gas region is below ambient pressure;
• and
• a fill valve, said fill valve selectively connecting the fill line to the fill port after the gas region is vented.