Thermostatic Vacuum Switching Valve (TVSV)
- Drain coolant from radiator and remove TVSV. Place threaded end of valve in container of ice water with thermometer. With temperature below 45°F (7°C), check that air flows from ports J to M and L and from ports K to N. See Fig 1.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Heat water to 63°-122°F (17-50°C). Check that air flows from ports K to N and L and from ports J to M.
- Continue heating water to above 154°F (68°C). Check that air flows from port K to ports M and L and does not flow from port J to any other port. If TVSV does not operate as described, replace it.