Thermostatic Air Cleaner: Operation: Notes

During engine warm-up, the temperature sensor switch applies vacuum to the vacuum motor. The air diverter valve is held in the ON position. Exhaust manifold heated air flows to the air cleaner. As the temperature of incoming air increases to 90°F, the temperature sensor opens the vacuum line to the atmosphere allowing spring pressure to push the valve to the OFF position. Air now flows from the outside, through the air cleaner duct to the carburetor.