Thermostatic Vacuum Switching Valve (TVSV)
- Drain coolant and remove TVSV. Place threaded end of valve in ice water with thermometer.
- With temperature below 45°F (7°C), check that air flows from pipe "A" to pipe "B" and "E", and from pipe "C" to "D". See Fig 1.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Heat water to 63-122°F (17-50°C). Check that air flows from pipe "C" to "D" and "E", and from pipe "A" to "B".
- Continue heating water to above 154°F (68°C). Check that air flows from pipes "C" to "B" and "E" and does not flow from pipe "J" to any other pipe. If problem is found, replace TVSV.