Cooling System Pressure Cap

All pressurized coolant bottles are equipped with a pressure cap. The pressure relief point (in pounds) is printed in yellow on top of the cap. The cooling system will operate at pressures up to 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. The valve opens when system pressure reaches the 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.