Cooling System: Testing and Inspection

ON-VEHICLE INSPECTION





1. INSPECT COOLING SYSTEM FOR LEAKS

CAUTION: To avoid the danger of being burned, do no 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.

HINT: 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" line.

HINT: If low, check for leaks and add "Toyota Long Life Coolant" or equivalent up to the "FULL" line.

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. INSPECT FINS BLOCKAGE





a. If fins are clogged, wash them with water or a steam cleaner and dry with compressed air.





NOTICE:
- If the distance between the steam cleaner and the core is too close, there is a possibility of damaging the fins, so keep the following Injection distance.
- If the fins are bent, straighten them with a screwdriver or pliers.
- Never apply water directly onto the electronic components.



INSPECTION





1. 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)

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 radiator 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 its 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 radiator 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 kgf/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 radiator cap.