Most vehicle owners can locate the radiator pressure cap, but not everyone understands how it works or why it is important.
Quick overview of the vehicle cooling system:
A running engine generates a phenomenal amount of heat as a result of combustion taking place in the engine. Engines are designed to run efficiently at temperatures ranging from 180 to 200 degrees F; the cooling system is designed to maintain the engine running temperature within this range. Pressurized cooling systems perform the following functions:
- Engine reaches the optimum operating temperature quickly
- Coolant temperature is maintained at the optimum
- Maintain coolant level as the coolant heats up and cools down
The purpose of radiator pressure caps:
As the coolant heats up or cools down it is transferred to and from the coolant overflow tank. When the pressure increases above the safe operating level, the radiator pressure cap releases some coolant from the system into the overflow tank. The radiator pressure cap operates with a spring loaded pressure valve, it opens when the system is too hot and closes as the system cools down and the coolant is drawn back into the system from the overflow tank. By moving coolant back and forth, the system pressure remains at the ideal rating.
When the engine is shut down it begins to cool, this results in a steady drop in pressure. The radiator pressure cap is that cooling system component that allows the coolant to return to the system from the overflow tank through the use of a second valve which responds to the vacuum created by the pressure drop.
The radiator pressure cap plays a significant role in the function of the cooling system, it recycles excess coolant so there are no pockets of air I the system and it prevents the collapse of the radiator hose from collapsing due to higher external pressures.
MotoRad offers a variety of pressure caps ranging from 4 PSI to over 30 PSI. Visit website for more information.