Thermostatic Air Cleaner: Description and Operation

Air Cleaner Assembly:

The air entering the engine is temperature controlled by an intake air preheating system. This system incorporates a vacuum operated, thermostatically controlled flap. This regulates the amount of cold and hot air entering the system.

TAC Flap:

When intake air temperature is below 20°C (68°F), vacuum is applied to the actuator and the flap closes off the cold air inlet. This allows heated air from the area around the exhaust manifold to be drawn in to the system. At intake air temperatures above 30°C (86°F), the flap closes off the heated air inlet and the cold air inlet is opened. At temperatures between the open and closed specification, vacuum is restricted by the temperature regulator, causing the flap to open partially and blend cold and heated air.