Product description
DENSO radiator pressure cap keeps the system pressure at 16 PSI, which avoids the coolant from boiling off even when it gets hotter considerably.
Because liquid expands as it gets hotter, the pressure cap allows coolant to escape to a reservoir tank when it expands. This is to keep a proper amount of coolant in the radiator when it expands.
The radiator pressure cap prevents trapping of air in the cooling system. The air in the system will cause poor cooling and cause corrosion to the cooling system.