Thermostatic Air Cleaner: Testing and Inspection

1. Verify that all vacuum hoses and the heat cowl to the air cleaner air duct are properly attached and are in good condition.
2. With a cold engine and ambient temperature less than 30 degrees C or 86 degrees F, the air control snorkel should be in the up or heat on position.
3. With the engine warmed up and running, check the air temperature entering the snorkel or at the sensor. When the air temperature entering the outer end of the snorkel is greater than 45 degrees C or 113 degrees F the door should be in the down position (heat off).
4. Remove the air cleaner from the engine and allow the air cleaner to cool down to 30 degrees C or 84 degrees F.

Fig. 23 Testing heated air intake control valve:

5. Apply 49.4 kPa (15 in. Hg) of vacuum to the thermostatic air valve vacuum motor, Fig. 23 and verify that the valve is in the up (heat on) position. If the valve does not rise check the vacuum motor for proper operation.
6. To test the vacuum motor, apply 32.5 kPa (10 in. Hg) of vacuum to the vacuum motor and verify that the door is in the full up position. If the vacuum motor does not operate properly replace the air cleaner body.