Cooling System Maintenance: Testing: Thermostat
- Visually inspect thermostat for corrosion and proper sealing. If satisfactory, suspend thermostat and thermometer in container of water. Do not allow either thermostat or thermometer to touch bottom of container as concentration of heat could cause an incorrect reading.
- Heat water until thermostat just begins to open. Note temperature at which thermostat begins to open. Compare to specification in table. See COOLANT SPECIFICATIONS. Replace thermostat if it does not open.
NOTE: Thermostat should open as water is heated.