On-Vehicle Inspection [12/2012 - ]: Procedure

INSPECT FOR COOLANT LEAK
WARNING:
To avoid the danger of being burned, do not remove the radiator reservoir cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator reservoir assembly.
1. Remove the reservoir cap.
2. Fill the radiator reservoir assembly with engine coolant, and then attach a radiator cap tester.
3. Warm up the engine.
4. Using the radiator cap tester, increase the pressure inside the radiator to 118 kPa (1.2 kgf/cm² , 17 psi), and then check that the pressure does not drop.
  If the pressure drops, check the hoses, radiator and engine water pump for leakage.
  
  If there are no signs of external coolant leaks, check the heater core, cylinder block and head.
5. Install the reservoir cap.
INSPECT ENGINE COOLANT LEVEL
1. Check that the engine coolant is between the LOW and FULL lines when the engine is cold.
  If the level is low, check for leakage and add TOYOTA Super Long Life Coolant (SLLC) 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.
INSPECT ENGINE COOLANT QUALITY
WARNING:
To avoid the danger of being burned, do not remove the radiator reservoir cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator.
1. Remove the reservoir cap.
2. Check for any excessive deposits of rust or scale around the reservoir cap and check that the coolant is free of oil.
  If the coolant is excessively dirty, replace the coolant.
3. Install the reservoir cap.