Thermostatic Air Cleaner: Testing and Inspection

1. Remove air cleaner cover and install temperature gauge tool No. J-22973 or equivalent--as close as possible to temperature sensor.
2. Install air cleaner cover. Do not install air cleaner cover wing nut.

Fig. 41 - TAC System Engine Off:

3. With engine OFF, check damper door position through snorkel opening. Snorkel passage should be open--Fig 41--if not check for damaged linkage.

Fig. 42 - TAC System Underhood Temperature Below 85 Degrees F.:

4. Start and operate engine at idle. With air temperature below 85° F.
- Snorkel passage should be closed--Fig 42.
5 When damper door begins to open snorkel passage, remove air cleaner cover.
- Tool reading should be between 85° F and 115° F.

Fig. 43 - TAC System Underhood Temperature Above 128 Degrees F.:

6. With air temperature 128° F, damper door should be fully open--Fig 43. If not check linkage for damage.
7. If damper door does not close completely or does not open at correct temperature, check vacuum motor as follows:
a. Switch engine "OFF" and disconnect diaphragm assembly vacuum hose from temperature sensor.
b. Connect a vacuum gauge and apply 9 inches Hg to vacuum diaphragm assembly through diaphragm hose--This can be done by blowing into the diaphragm hose.
c. Damper door should completely close snorkel passage when vacuum is applied.
d. If damper door does not close, check linkage for damage and diaphragm for a vacuum leak.
e. With vacuum applied, bend or clamp diaphragm hose. Damper door should remain in closed position. If not, replace diaphragm assembly.