COOLING SYSTEM ON-VEHICLE INSPECTION

PROCEDURE

1. PRECAUTION

   Note

   
   

   • The coolant (Toyota genuine FC stack coolant) is an exclusive coolant.

   • The coolant (Toyota genuine FC stack coolant) cannot be reused, so when filling, be sure to fill with new coolant (Toyota genuine FC stack coolant).

   • To prevent degradation of coolant (Toyota genuine FC stack coolant) performance, do not add or fill any other substances such as tap water or battery electrolyte refill liquid.

   • Do not use cotton work gloves or other gloves that could shed fibers.

   • DO NOT use any container that has previously been used to fill substances such as oil.

   • To prevent foreign matter from contaminating the coolant (Toyota genuine FC stack coolant) passages, wash out the prepared container with tap water, then wipe away any water remaining inside the container before using it.

   • If the coolant (Toyota genuine FC stack coolant) passages are filled incorrectly, follow the countermeasures according to "Countermeasures when coolant (Toyota genuine FC stack coolant) passages are filled incorrectly".

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   • When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work.

2. INSPECT FOR COOLANT (FC STACK COOLANT) LEAK

   CAUTION:

   
   

   • When coolant (Toyota genuine FC stack coolant) is hot, do not remove the radiator cap sub-assembly.

   • Fluid and steam may spray out due to high pressure, possibly resulting in burns.

   

   
   

   1. Remove the radiator cap sub-assembly.

   2. Fill the FC radiator assembly with new coolant (Toyota genuine FC stack coolant), and then install a radiator cap tester.

   3. 

      Pump the radiator cap tester to 108 kPa (1.1 kgf/cm², 16 psi), and then check that the pressure does not drop and there are no leaks from the following locations.

      
      

      • Each hose

      • FC radiator assembly

      • Sub-radiator assembly

      • FC cooling water temperature control valve

      • FC cooling water pump assembly

      • FC cooling water ion exchanger assembly

      • FC stack assembly

      • Heater water with motor pump assembly

      • 3 way valve

      • Electric heater sub-assembly

      • Heater radiator unit sub-assembly

   4. Remove the radiator cap tester.

   5. Install the radiator cap sub-assembly.

   6. Drive the vehicle for approximately 15 minutes.

      CAUTION:

      When driving the vehicle, make sure to obey all posted speed limits and traffic laws.

   7. After driving the vehicle, re-check to make sure that no coolant (Toyota genuine FC stack coolant) is leaking from the coolant passages.

3. INSPECT COOLANT (FC STACK COOLANT)

   
   

   1. 

      When the FC system is cold, check that the fluid level in the reserve tank is between the FULL and LOW lines.

      Note

      Do not fill any coolant other than the specified coolant (Toyota genuine FC stack coolant).

      Tech Tips

      
      

      • If the coolant (Toyota genuine FC stack coolant) level is low, perform coolant leak inspection, and fill new coolant (Toyota genuine FC stack coolant).

      • The reserve tank hose is installed with 2 clamps as shown in the illustration.

4. INSPECT COOLANT (FC STACK COOLANT)

   CAUTION:

   
   

   • When coolant (Toyota genuine FC stack coolant) is hot, do not remove the radiator cap sub-assembly.

   • Fluid and steam may spray out due to high pressure, possibly resulting in burns.

   

   
   

   1. Remove the radiator cap sub-assembly.

   2. Check that there are no excessive deposits of rust or scale around the radiator cap sub-assembly and coolant (Toyota genuine FC stack coolant) hole. Also, the coolant (Toyota genuine FC stack coolant) should be free of oil.

      If excessively dirty, replace the coolant (Toyota genuine FC stack coolant).

   3. Install the radiator cap sub-assembly.