Description-Diesel Engines
WARNING: This page is about a different car, the 2007 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
| 1 - FILLER NECK SEAL |
| 2 - VACUUM VENT VALVE (SHOWN IN SEALING POSITION) |
| 3 - PRESSURE RATING |
| 4 - PRESSURE VALVE |
All vehicles are equipped with a pressure cap. This cap releases pressure at some point within approximately 145 kPa (21 psi). The pressure relief point (in pounds) (3) 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 approximately 145 kPa (21 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.