Thermostat Test Procedure Using Tempil Sticks
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The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil like device. It has a wax material containing certain chemicals which melt at a given temperature. Temperature sticks can be used to determine a thermostat's operating range, by rubbing 87°C (188°F) and 97°C (206°F) sticks on the thermostat housing.
- Use a tempil stick in order to find the opening and the closing temperatures of the coolant thermostat.
- J 24731 -188 tempil stick melts at 87°C (188°F). See Special Tools and Equipment . The thermostat should begin to open.
- J 24731 -206 tempil stick melts at 97°C (206°F). See Special Tools and Equipment . The thermostat should be fully open.
- Replace the coolant thermostat if it does not operate properly between this temperature range.