Coolant Reservoir: Description and Operation

Trapped air in the cooling system must be removed. A pressurized degas bottle system is used which continuously separates the air from the cooling system.
- When the water thermostat is open, coolant flows through both the small hose from the top of the radiator outlet tank and the degas tube and hose assembly from the engine to the degas bottle.
- The degas bottle separates any trapped air from the coolant and replenishes the system through its degas hose.
- The degas bottle serves as the location for:
- service fill.
- coolant expansion during warm-up.
- system pressurization from the pressure relief cap.
- air separation during operation.

- The degas bottle is designed to have approximately 0.5-1 liter (0.53-1.06 quarts) of space when cold to allow for Coolant expansion.

NOTE: When the water thermostat is closed, coolant flows through the degas tube and hose assembly from the lower radiator hose to the degas bottle.