Thermal Vacuum Valve: Testing and Inspection

Fig. 25 Testing BVSV - Open Position:

Fig. 27 Testing BVSV - Closed Position:

M/T MODELS

1. Drain the coolant from the radiator into a suitable container.
2. Unscrew and remove the BVSV from the intake manifold.
3. Place the BVSV in a pan of cool water, (below 104°F). Fig. 25
4. Check that air flows from pipe M through pipes L and N.
5. Heat the BVSV to above 129°F with hot water. Fig. 27
6. Check that both pipes L and N are closed to air flow from pipe M.
7. If a problem is found, replace the BVSV.
8. Apply a suitable sealant to the BVSV threads and reinstall on engine.

Fig. 26 Testing BVSV - Open Position:

Fig. 27 Testing BVSV - Closed Position:

A/T MODELS

1. Drain the coolant from the radiator into a suitable container.
2. Unscrew and remove the BVSV from the intake manifold.
3. Place the BVSV in a pan of cool water, (below 104°F). Fig. 26
4. Blow air into either pipe and check that the BVSV is open, (air passes).
5. Heat the BVSV to above 129°F with hot water. Fig. 28
6. Air should NOT pass through the valve, (BVSV closed).
7. If a problem is found, replace the BVSV.
8. Apply a suitable sealant to the BVSV threads and reinstall on engine.