Air Cleaner - Thermostatic: Operation: Notes
When temperature of air entering air cleaner is less than calibrated temperature of temperature sensor, sensor closes. This allows engine vacuum to operate vacuum motor.
When engine vacuum is applied to vacuum motor, door closes off outside air. Air is then drawn into air cleaner from around exhaust manifold.
As air inside air cleaner warms, temperature sensor begins to open. This gradually bleeds off vacuum to vacuum motor. As vacuum to vacuum motor decreases, air control door begins to open.
As air control door opens, outside air is allowed to enter air cleaner assembly. When air entering air cleaner reaches a predetermined temperature, air control door opens completely. This completely closes off air from around exhaust manifold.