Cooling System Pressure Cap

All radiators are equipped with a pressure cap. This cap releases pressure at some point within a range of 145 kPa (21 psi). The pressure relief point (in pounds) is printed in yellow on top of the cap. The cooling system will operate at pressures of 145 kPa (21 psi) above atmospheric pressure. This results in a higher coolant boiling point allowing increased radiator cooling capacity. The cap contains a spring-loaded pressure relief valve. This valve opens when system pressure reaches the release range of 145 kPa (21 psi). A rubber gasket seals the cap to maintain vacuum during coolant cool-down and to prevent leakage when system is under pressure.