Thermostat: Service and Repair

THERMOSTAT

REMOVAL
1. Drain cooling system and tighten drain plug.
2. Disconnect thermostat cap from intake manifold.




3. Remove thermostat.





INSPECTION
1. Make sure that air bleed valve of thermostat is clean. Should this valve be clogged, engine would tend to over- heat.
2. Check to make sure that valve seat is free from foreign matters which would prevent valve from seating tight.
3. Check thermostat seal for breakage, deterioration or any other damage.





4. Check thermostatic movement of wax pellet as follows:
1. Immerse thermostat in water, and heat water gradually.
2. Check that valve starts to open at specific temperature.
3. If valve starts to open at a temperature substantially below or above specific temperature, thermostat unit should be replaced with a new one. Such a unit, if re-used, will bring about overcooling or overheating tendency.





INSTALLATION
1. When positioning thermostat on intake manifold, be sure to bring its air bleed valve to front side of engine.





2. Install thermostat cap to intake manifold and tighten bolts to specified torque.

Tightening torque
- (a): 13 Nm (1.3 kg.m, 9.5 lb-ft)

3. Fill cooling system.