Thermostatic Vacuum Switching Valve (TVSV): Starlet
- Drain coolant from radiator and remove TVSV. Place threaded end of valve in container of water with thermometer. With temperature below 106°F (41°C), check that air flows from pipe "J" to pipe "N" and does not flow from pipe "L" to pipe "N". See Figure.
- Heat water to above 131°F (55°C). Check that air flows from pipe "J" to pipe "K" and from pipe "L" to pipe "M". If TVSV does not operate as described, replace it.