ON−VEHICLE INSPECTION
1. INSPECT COOLING SYSTEM FOR LEAKS
CAUTION: Do not remove the radiator cap while the engine and radiator are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.
Fill the radiator with coolant and attach a radiator cap tester.
Warm up the engine.
Using the radiator cap tester, increase the pressure inside the radiator to 118 kPa (1.2 kgf/cm2, 17.1 psi), and check that the pressure does not drop.
If the pressure drops, check the hoses, radiator or water pump for leaks. If no external leaks are found, check the heater core, cylinder block and head.
Inspect cooling system for leaks
2. CHECK ENGINE COOLANT LEVEL AT RESERVOIR
a. The engine coolant level should be between the ”LOW” and ”FULL” lines, when the engine is cold.
If low, check for leaks and add ”Toyota Super Long Life Coolant” or similar high quality ethylene glycol based non−silicate, non−amine, non−nitrite, and non−borate coolant with long−life hybrid organic acid technology up to the ”FULL” line.
3. CHECK ENGINE COOLANT QUALITY
a. Remove the radiator cap.
CAUTION: Do not remove the radiator cap while the engine and radiator are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.
Check if there is any excessive deposits of rust or scale around the radiator cap and radiator filler hole.
Also, the coolant should be free from oil.
HINT: If excessively dirty, replace the coolant.
Reinstall the radiator cap.
INSPECTION
1. INSPECT THERMOSTAT
HINT: The thermostat is numbered with the valve opening temperature.
Immerse the thermostat in water and gradually heat the water.
Check the valve opening temperature.
Valve opening temperature: 80 to 84 C (176 to 183 F)
If the valve opening temperature is not as specified, replace the thermostat
c. Check the valve lift.
Valve lift: 10 mm (0.394 in.) or more at 95 C (203 F)
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)).
If not closed, replace the thermostat.
2. INSPECT WATER OUTLET 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 steps a. and b. below, 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 being released from the vacuum valve.
Pump speed: 1 push every 3 seconds or more
NOTICE: Push the pump at a constant speed.
If air is not being released from the vacuum valve, replace the reservoir cap.
b. Pump the tester and measure the relief valve opening pressure.
Pump speed: 1 push within 1 second
NOTICE: The pump speed above should be followed for the first pump only. it will close the vacuum valve. Once the vacuum is colosed, the pump speed can be reduced.
Standard opening pressure: 69.0 to 112.8 kPa (0.70 to 1.15 kgf/cm2, 10.0 to 16.4 psi)
HINT: Use the tester’s maximum reading as the opening pressure. If the maximum reading is less than the minimum opening pressure above, replace the radiator cap.