Thermal Vacuum Valve: Testing and Inspection

Fig. 41 Testing BVSV - Closed Position:

Fig. 42 Testing BVSV - Open Position:

1. Drain the coolant from the radiator into a suitable container.
2. Unscrew and remove the BVSV.
3. Cool the BVSV to below 40°C (104°F) with cold water.
4. Blow air into either inlet pipe and check that air does NOT pass through valve. Fig. 41
5. Heat the BVSV to above 54°C (129°F) with hot water.
6. Blow air into either inlet pipe and check that air does pass, (valve open). Fig. 42
7. If a problem is found, replace BVSV.
8. Apply a suitable sealing compound to the BVSV threads and reinstall.
9. Refill the radiator with coolant.