Thermostatic Air Cleaner: Testing and Inspection

Fig. 46 Observing The Operation Of The Heated Intake Air Control Valve:

INTAKE AIR TEMPERATURE CONTROL SYSTEM INSPECTION

1. Remove the air cleaner cover.
2. Run the engine at idle and verify that when thermo sensor temperature is less than 30 degrees C or 86 degrees F the cold air inlet is closed.
3. Allow the engine to warm up until thermo sensor temperature exceeds 45 degrees C or 113 degrees F and verify that the hot air inlet is closed.

Fig. 47 Cooling The Heated Intake Air Thermo Control Valve:

4. If necessary compressed air can be used to cool the thermo sensor during testing.

Fig. 48 Testing The Operation Of The Heated Intake Air Control Valve:

AIR CONTROL VALVE INSPECTION

1. Remove the air cleaner.
2. Disconnect the vacuum hose from the air control valve and connect a hand vacuum pump to the valve nipple.
3. Apply a vacuum of 67 kPa or 19.7 in. Hg and verify that the diaphragm chamber is leak tight.

Fig. 49 Observing The Operation Of The Heated Intake Air Control Valve:

4. Apply less than 9 kPa or 2.8 in. Hg and verify that the cold air inlet opens.
5. Increase vacuum to 25 kPa 7.5 in. Hg and verify that the cold air inlet closes.
6. Reconnect vacuum control hoses.

Fig. 50 Connecting A Vacuum Pump To Heated Intake Air Thermo Control Valve:

THERMO SENSOR INSPECTION

1. Connect a hand vacuum pump to the thermo sensor and verify that when thermo sensor temperature is less than 30 degrees C or 86 degrees F that vacuum does not leak through the thermo sensor.
2. Warm up the thermo sensor with a heat gun or hair dryer until thermo sensor temperature exceeds 45 degrees C or 113 degrees F and verify that vacuum leaks through the thermo sensor.