Toyota Tacoma 2015-2018 Service Manual: Cooling System

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. INSPECT FOR COOLANT LEAK

CAUTION:

Do not remove the radiator cap sub-assembly, cylinder block drain cock plug or radiator drain cock plug while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.

(a) Remove the radiator cap sub-assembly.

(b) Fill the radiator assembly with engine coolant and install a radiator cap tester.

(c) Warm up the engine.

(d) Using the radiator cap tester, increase the pressure inside the radiator assembly to 118 kPa (1.2 kgf/cm2, 17 psi), and then check that the pressure does not drop.

If the pressure drops, check the hose, radiator assembly and engine water pump assembly for leakage. If no external leakage is found, check the heater core, cylinder block sub-assembly and cylinder head sub-assembly.

(e) Remove the radiator cap tester.

(f) Install the radiator cap sub-assembly.

2. INSPECT ENGINE COOLANT LEVEL IN RESERVOIR

(a) The engine coolant should be between the LOW and FULL lines when the engine is cold. Text in Illustration *a FULL Line *b LOW Line If the engine coolant is below the LOW line, check for leakage and add TOYOTA Super Long Life Coolant (SLLC) or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, non-borate coolant with long-life hybrid organic acid technology to the FULL line. NOTICE: Never use water as a substitute for engine coolant.

3. INSPECT ENGINE COOLANT QUALITY

CAUTION:

Do not remove the radiator cap sub-assembly, cylinder block drain cock plug or radiator drain cock plug while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.

(a) Remove the radiator cap sub-assembly.

(b) Check for excessive deposits of rust or scales around the radiator cap sub-assembly and radiator filler hole. Also, the engine coolant should be free of oil.

If the engine coolant is excessively dirty, replace the engine coolant.

(c) Install the radiator cap sub-assembly.