Cooling System: Testing and Inspection

ON-VEHICLE INSPECTION





1. INSPECT COOLING SYSTEM FOR LEAKS

CAUTION: To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator are still hot, as fluid and steam can be blown out under pressure.

a. Fill the radiator with coolant and attach a radiator cap tester.
b. Warm up the engine.
c. Pump it to 118 kPa (1.2 kgf/cm2, 17.1 psi), and check that the pressure does not drop.
If the pressure drops, check to hoses, radiator or water pump for leaks. If no external leaks are found, check the heater core, cylinder block and head.
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 Long Life Coolant" or equivalent up to the "FULL" line.

DO NOT FURTHER DILUTE PRE-MIXED MANUFACTURER APPROVED ETHYLENE GLYCOL BASED COOLANT IF USED.
MIX ACCORDING TO THE MANUFACTURER'S DIRECTIONS.


3. CHECK ENGINE COOLANT QUALITY
a. Remove the radiator cap.

CAUTION: To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator are still hot, as fluid and steam can be blown out under pressure.

b. Check if there is any excessive deposits of rust or scale around the radiator cap and radiator filler hole; the coolant should be free from oil.

HINT: If excessively dirty, replace the coolant.

c. Reinstall the radiator cap.

4. THERMOSTAT





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





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





5. 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.

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.

If air is not coming 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: This pump speed Is for the first pump only (in order to close the vacuum valve). After this, the pump speed can be reduced.

Standard opening pressure: 93 - 122 kPa (0.95 - 1.25 kgf/cm2, 13.4 - 17.6 psi)
Minimum opening pressure: 78 kPa (0.8 kgf/cm2, 11.2 psi)

HINT: Use the tester's maximum reading as the opening pressure. If the opening pressure is less than minimum, replace the reservoir cap.