Thermostat: Testing and Inspection

INSPECTION AFTER REMOVAL
^ Make sure that valves both in thermostat and water control valve are completely closing at normal temperature.





^ Place a thread so that it is caught in the valves of the thermostat and water control valve. Immerse fully in a container filled with water. Heat while stirring. (The example in the figure shows thermostat.)
^ The valve opening temperature is the temperature at which the valve opens and falls from the thread.
^ Continue heating. Check the maximum valve lift.

NOTE: The maximum valve lift standard temperature for water control valve is the reference value.

^ After checking the maximum valve lift, lower the water temperature and check the valve closing temperature.

Standard Values:

^ If the malfunctioning condition, when closing valve at normal temperature, or measured values are out of the standard, replace thermostat and/or water control valve.

INSPECTION AFTER INSTALLATION
^ Check for leaks of engine coolant using radiator cap tester adapter [SST: EG17650301 (J33984-A)] and radiator cap tester (commercial service tool).
^ Start and warm up engine. Visually check if there is no leaks of engine coolant.