Thermal Vacuum Valve: Testing and Inspection

Fig. 11 Testing water thermo valve for air switching valve:

1. Remove water thermo valve.
2. Immerse valve in container of water, then slowly heat water while observing temperature.
3. When coolant temperature is 131°F. or above for 1982-83 Federal high altitude vehicles, or 122°F. or above for other vehicles, blow air into hose, Fig. 11, and ensure air flows from other hose.
4. If test results are unsatisfactory, replace water thermo valve.