3.6L, 5.7L

WARNING: This page is about a different car, the 2015 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Radiator Pressure Cap - Typical

Courtesy of CHRYSLER GROUP, LLC

1 - FILLER NECK SEAL

2 - VACUUM VENT VALVE

3 - PRESSURE RATING

4 - PRESSURE VALVE

All cooling systems are equipped with a pressure cap. For all engines, the pressure cap is located on top of the radiator outlet tank. The cap releases pressure at some point within a range of 97-to-124 kPa (14-to-18 psi). The pressure relief point (in pounds) is engraved on top of the cap

The cooling system will operate at pressures slightly 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 97-to-124 kPa (14-to-18 psi).

A rubber gasket seals the radiator filler neck. This is done to maintain vacuum during coolant cool-down and to prevent leakage when system is under pressure.