Thermostatic Air Cleaner: Testing and Inspection

INSPECTION AND REPAIR OF ACL SYSTEM

1. Vacuum Motor and Hot Air Control
With the vacuum hose, connect vacuum motor inlet pipe directly with nipple on intake manifold.
When vacuum pressure is nearly zero, look through air intake side of air cleaner. Check to be sure hot air control valve is closed completely.
Start and hold engine running at idle. Check to see if the hot air control valve closes completely. Also, check that valve works smoothly.






2. Thermo-Sensor
Remove air cleaner from engine. Attach thermocouple type thermometer to sensor and replace cover. Install air cleaner in position on engine, after allowing it to cool. Start engine and check for the following:
- Look through air intake side of air cleaner. Check that hot air switching valve begins to move in toward fresh air intake side, when engine is started.
- Take thermometer reading when the valve begins to open the outside air passage. You can see the valve move by looking in the fresh air entrance. Take measurement several times to obtain an average value. Thermometer reading may vary each time test is made. If measured temperature deviates from the range of 100° - 111°F (38°-44°C), replace thermosensor assembly.






3. Hot Idle Compensator

Checking Hot idle Compensator
1) Remove rubber hose from intake manifold.
2) Check temperature around Hot Idle compensator with thermometer.
3) If temperature is between 115°F (46°C) and 126°F (52°C), air comes out of Hot Idle Compensator, when air is blown into hose.
Replace Hot Idle Compensator if defective.
4) After checking, connect hose to intake manifold and install air cleaner.

NOTE:
- To check for operation when Hot Idle compensator (bimetal) temperature is lower than 115°F (46°C), warm it up with hair drier or photo light before checking.
- Never touch bimetal or valve in Hot Idle Compensator.