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. Fluid and steam can be blown out under pressure.
a. Fill the radiator with coolant, then attach the radiator cap tester.
b. Warm up the engine.
c. Pump it up to 177 kPa (1.8 kgf/cm2, 25.6 psi), then check that pressure does not drop.
HINT: If the pressure drops, check the hose, radiator and water pump for leaks. If no external leaks are found. check the heater core, cylinder block and cylinder head.
2. CHECK ENGINE COOLANT LEVEL AT RESERVOIR
a. Check that the coolant level in the reservoir tank is between "F" and "L" 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.
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. Fluid and steam can be blown out under pressure.
b. Check that there are no excessive collections of rust or scale around the radiator cap or radiator filler hole.
HINT: If excessively dirty, replace the coolant.
c. Attach the radiator cap.
4. INSPECT FIN BLOCKAGE
a. If the 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 core is too close, the fins could be damaged. So keep the following injection distance.
- If the fins are bent, straighten them with a screwdriver or pliers.
- Be careful not to pour water directly onto electronic components.
INSPECTION
1. INSPECT THERMOSTAT
HINT: The thermostat is imprinted with the valve opening temperature.
a. Immerse the thermostat in the water, then gradually heat the water.
b. Check the valve opening temperature.
Valve opening temperature: 80 to 84°C (176 to 183°F)
HINT: If the valve opening temperature is not as specified, replace the thermostat.
c. Check the valve lift.
Valve lift
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 temperature (below 77°C (171°F)).
If not fully closed, replace the thermostat.
2. INSPECT RADIATOR CAP SUB-ASSY
NOTICE:
- If the water filler cap is dirty, clean it with water.
- Before using the radiator cap tester, wet the relief valve and pressure valve with coolant or water.
a. Using a radiator cap tester, slowly pump the tester and check that the air is coming form the vacuum valve.
Pumping speed: 1 push/3 seconds or more
NOTICE:
- Pump the tester at a constant speed.
- Slant the radiator cap tester at an angle of over 30° as shown in the illustration when checking. If air is not coming from the vacuum valve, replace the radiator cap.
b. Pump the tester, then measure the relief valve opening pressure.
Pumping speed: 1 push/1 second or more
NOTICE:
- This pumping speed is for only the first pumping to close the vacuum valve. After the first pumping, the pumping speed can be reduced.
- Slant the radiator cap tester at an angle of over 30° as shown in the illustration when checking.
Standard opening pressure: 74 to 103 kPa (0.75 to 1.05 kgf/cm2, 10.7 to 14.9 psi)
Minimum opening pressure: 59 kPa (0.6 kgf/cm2, 8.5 psi)
HINT: Use the tester's maximum reading as the opening pressure.
If the opening pressure is less than minimum, replace the radiator cap.