Thermostatic Air Cleaner: Testing and Inspection

SYSTEM OPERATIONAL CHECK

1. Start engine and warm up to operating temperature, then shut engine off.
2. Remove air cleaner cover.
3. Cool thermo valve below 38°C (100°F) by blowing compressed air onto it or by placing a piece of ice on top of valve.
4. Start engine and observe damper valve. Damper valve should be closed to outside air and open to heated air from hot air tube.
5. As intake air heats the thermo valve, the damper door should begin to open to outside air. When intake temperature heats valve over approx. 50°C (120°F), the damper valve should be fully open to outside air, and the thermo valve should open the air bleed to ambient air.

Inlet Temperature Compensator (ITC) Valve:

INLET TEMPERATURE CONTROL VALVE

1. Check to see that valve is open from vacuum source port to vacuum motor port when below approx. 38°C (100°F), and that no ambient air is allowed into valve. See "cold condition" in diagram.
2. Check to see that ambient air is allowed into the vacuum motor side of valve when temperature is between approx. 44°C and 50°C (100°F-111°F). See "normal condition" in diagram.
3. Check to see that ambient air is allowed into vacuum side of valve when temperature of valve is over approx. 50°C (120°F). See "hot condition" in diagram.


VACUUM MOTOR/DAMPER VALVE

1. Disconnect vacuum hose to vacuum motor.
2. Connect vacuum pump and apply approx. 200mmHg (8"Hg) vacuum. Damper valve should close air cleaner to outside air, and should hold vacuum.
3. Disconnect vacuum pump. Damper valve should open air cleaner to outside air.
4. Replace if defective.