To determine if improper engine coolant level is causing high engine coolant temperature,
perform the following:
1. Visually inspect the radiator coolant level; refer to OEM guidelines.
2. Examine the results.
[a] If the radiator coolant level is within 2.0 in. (approximately 50 mm) of the radiator
filler neck, check insufficient radiator air circulation; refer to section 13.2.
[b] If the radiator coolant level is not within 2 in. (approximately 50 mm) of the radiator
filler neck, refer to section 13.1.1.
13.1.1
Improper Coolant Level Resolution
Perform the following steps to resolve improper coolant level:
1. Fill coolant system to correct level; refer to appropriate service manual, preventive
maintenance chapter.
2. Verify coolant level resolution; refer to section 13.1.1.1.
13.1.1.1
Test Engine with Proper Coolant Level
Perform the following to determine if proper coolant level resolved high engine coolant
temperature:
1. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately 5 minutes,
allowing the engine coolant to reach normal operating range.
[a]If the engine coolant temperature is 88-96°C (190-210°F). Shut down the engine.
Determine the cause of low coolant level.Refer to section 13.1.1.2
[b]If the engine coolant temperature is not 88-96°C (190-210°F), shut down the engine.
Check for insufficient radiator air circulation; refer to section 13.2.
13.1.1.2
Pressure Test the Cooling System
Perform the following to pressure test the cooling system:
1. Pressure test the cooling system with a pressure tester.
[a] Check for external leaks on the engine, radiator, all coolant hoses and the heater
core in the cab.
[b] Repair any external leaks and perform the procedure in found in section 13.1.1.3.
[c] If there are no external leaks perform the procedure found in section 13.2.
13.1.1.3
Test Engine with Coolant Leaks Repaired
Perform the following steps to test the engine with coolant leaks repaired:
1. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately five minutes
allowing the engine coolant to reach normal operating range.
[a] If engine the coolant temperature is 88-96°C (190-210°F). Shut down the engine
no further troubleshooting is required.
[b] If the engine coolant temperature is not 88-96°C (190-210°F), shut down the engine.
Check for insufficient radiator air circulation. Refer to section 13.2.
