WATER THERMO VALVE TEST

1. Drain the cooling system until the coolant level is below the intake manifold. Remove the water thermo valve from the manifold.

   CAUTION
   When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

2. Place a valve in a container of water. Attach a length of vacuum hose to each of the two fittings.
3. Gradually heat the water while observing the temperature.
4. By blowing through one of the vacuum hoses, you will be able to tell when the valve opens. The valve should block the passage of air until the water temperature reaches approximately 115°F (46°C). If this is not the case, the valve is faulty and must be replaced.