Inspecting Thermostats and Testing Opening Temperature

RG5971-UN-23NOV97

Thermostat And Thermometer In Water

1. Remove thermostats. (See REMOVING THERMOSTATS earlier in this section.)

2. Visually inspect thermostats for corrosion or damage. Replace thermostats as a matched set as necessary.

3. Inspect thermostat with wiggle wire in vent notch. If wire movement is restricted, replace thermostat if cleaning does not free movement.

4. CAUTION: DO NOT allow thermostat or thermometer to rest against the side or bottom of container when heating water. Either may rupture if overheated.

   Suspend thermostats and a thermometer in a container of water.

5. Stir the water as it heats. Observe opening action of thermostat and compare temperatures with specifications. See GENERAL ENGINE SPECIFICATIONS in Specification Section.

   NOTE: Due to varying tolerances of different supplies, initial opening and full open temperatures may vary slightly from specified temperatures.

6. Remove thermostat and observe its closing action as it cools. In ambient air the thermostat should close completely. Closing action should be smooth and slow.

7. If any one thermostat is defective, replace both thermostats.