Thermal Vacuum Valve: Testing and Inspection

Thermovalve (Choke Breaker Port) Test:

THERMO VALVE INSPECTION

1. Disconnect the port "A" vacuum hose from the thermovalve and connect a hand vacuum pump.
2. While engine coolant temperature is less than 61°F+/-5° (16°C+/-3°) attempt to apply vacuum to port "A" and verify that vacuum leaks.
3. Warm up engine until coolant temperature exceeds 64°F+/-4° (18°C+/-2°).
4. Apply vacuum and verify that vacuum holds.

NOTE: This procedure tests the choke breaker vacuum port only. For tests of the other vacuum ports, refer by system affected to EMISSION CONTROLS.