Cooling System: Testing and Inspection
ON-VEHICLE INSPECTIONS
COOLANT
1. CHECK ENGINE COOLANT LEVEL AT RADIATOR RESERVOIR
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. Do not use plain water alone.
DO NOT FURTHER DILUTE PRE-MIXED MANUFACTURER APPROVED ETHYLENE GLYCOL BASED COOLANT IF USED.
MIX ACCORDING TO THE MANUFACTURER'S DIRECTIONS.
2. CHECK ENGINE COOLANT QUALITY
a. Remove the radiator cap from the water outlet.
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. There should not be any excessive deposits of rust or scale around the radiator cap or water outlet filler hole, and the coolant should be free from oil.
If excessively dirty, clean the coolant passages and replace the coolant.
c. Reinstall the radiator cap.
RADIATOR
1. REMOVE 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.
2. INSPECT RADIATOR CAP
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 steps (a) and (b) below, keep the radiator cap 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.
If air is not coming from the vacuum valve, replace the radiator 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 to 123 kPa (0.95 to 1.25 kgf/cm2, 13.5 to 17.8 psi)
Minimum opening pressure: 78 kPa (0.8 kgf/cm2, 11.4 psi)
HINT: Use the tester's maximum reading as the opening pressure.
If the opening pressure is less than minimum, replace the radiator cap.
3. INSPECT COOLING SYSTEM FOR LEAKS
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 cheek 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.
4. REINSTALL RADIATOR CAP
INSPECT WATER PUMP
NOTICE: Be sure to do checking when the engine coolant is charged.
a. Remove the drive belt.
b. Turn the pulley, and check that the water pump bearing moves smoothly and quietly.
If necessary, replace the water pump.
c. Remove the water pump pulley.
d. Visually check the inlet hole and drain hole for coolant leakage.
If leakage is found, replace the water pump.
e. Reinstall the water pump pulley.
f. Reinstall the drive belt.