Thermostat and Radiator Cap Inspection

INSPECTION
1. THERMOSTAT





HINT: The thermostat is numbered with the valve opening temperature.





a. Immerse the thermostat in water an gradually heat the water.
b. Check the valve opening temperature.
Valve opening temperature: 80 - 84°C (176 - 183°F)

HINT: If the valve opening temperature is not as specified, replace the thermostat.





c. Check the valve lift.
Valve lift: 10 mm (0.39 inch) or more at 95°C (203°F)

HINT: If the valve lift is not as specified, replace the thermostat.

d. Check that the valve is fully closed when the thermostat is at low temperatures (below 77°C (171°F)).

HINT: If not closed, replace the thermostat.

2. RADIATOR CAP SUB-ASSY

NOTICE:
- If the reservoir cap has contaminations, always rinse it with water.
- Before using a radiator cap tester, wet the relief valve and pressure valve with engine coolant or water.
- when performing step a. and b., keep the tester at an angle of over 30° above the horizontal.





a. Using a radiator cap tester, slowly pump the tester and check that air is coming from the vacuum valve.
Pump speed: 1 push / (3 seconds or more)

NOTICE: Push the pump at a constant speed.

HINT: Pump speed: 1 push / (3 seconds or more)
- If air is not coming from the vacuum valve, replace the reservoir cap.

b. Pump the tester and measure the relief valve opening pressure.
Standard opening pressure: 74 - 103 kPa (0.75 - 1.05 kgf/cm2, 10.7 - 14.9 psi)
Minimum opening pressure: 59 kPa (0.6 kg/cm2, 8.5 psi)

NOTICE: This pump speed is for the first pump only (in order to close the vacuum valve). After this, the pump speed can be reduced.

HINT:
- Pump speed: 1 push within 1 second
- Use the tester's maximum reading as the opening pressure.
- If the opening pressure is less than minimum, replace the reservoir cap.