Bi-Metallic Vacuum Switching Valve (BVSV)
- Drain coolant and remove BVSV valve. Place sensing portion in cool water, but do not allow water into valve.
- Cool BVSV to below 86°F (30°C). Blow air into top port and check that air does not escape through bottom port.
- Heat BVSV to above 111°F (44°C). Blow air into top port and check that air escapes through bottom port.
- Apply liquid sealer to threads of BVSV and reinstall. Fill radiator with coolant. If problem is found, replace BVSV.