Aftermarket Tips from RDO Equipment Co.
The majority of hot weather overheating problems are found to be either low air flow or low coolant flow. Plugged radiators, fans on backwards, missing baffles, or damaged shrouds are frequent causes of low air flow. Low coolant flow can be due to failed water pumps, plugged radiator tubes, collapsed hoses, or low coolant level. In addition, trapped air in the cooling system, is something else that can cause an overheat issue.
Thermostats are the least likely part in a cooling system to fail, yet they are the first part to be replaced when a cooling system complaint is received.
With radiator inlet and outlet temperatures, we can determine whether the problem is related to air flow or coolant flow. If the temperature differential between the inlet and outlet is larger than the system is designed to produce, it is indicative of low coolant flow. If the temperature differential is smaller than the designed amount, it indicates low air flow.
In order to know if there is a problem with the cooling system, the designed temperature differential across the radiator must be known. This can vary, depending on cooling system design. For nearly all John Deere diesel engines, the temperature differential should be around 10°F (6°C) when running at full power and thermostat fully open.
Higher temperature differentials such as 20°F (11°C) indicate low coolant flow. The low coolant flow will result in slower rate through the radiator. The longer the coolant spends in the radiator the cooler it will become. Hence the temperature differential will be greater than 10°F (6°C).
Temperature differentials less than 10°F (6°C) indicate low air flow. Low air flow reduces the cooling efficiency of the radiator. Since the coolant is spending the same amount of time in the radiator as it normally would, and cooling efficiency is less the coolant will not lose as much heat as it should. Hence the temperature differential will be less than 10°F (6°C).
Cooling System Tips:
- Make sure coolant/recovery tank is full. Check daily and for leaks.
- Make sure fan/water pump belts (If equipped) are tight and in good condition.
- Make sure you are using Cool-Gard II Antifreeze recommended for John Deere Engines and change at required intervals to prevent internal cooling system damage and corrosion build up in the radiator.
- The new coolant/ Anti-Freeze is compatible with all engines, but older, generic coolant should not be used in the new IT and FT engines.
- Make sure the radiator hoses are not damaged or soft from age.
- Make sure fan and shroud are in good condition, no missing pieces. Air flow is important.
- Make sure you clean out debris, (restriction) between the radiator, coolers, and AC.
- Your radiator might look clean externally, but to see if it is clean you should be able to see through it. By shining a light on one side you should see light on the other side, every square inch of the radiator surface.
- Your radiator cap plays an important part in the cooling system, maintaining the pressure in the cooling system. Replacing the radiator cap occasionally improves cooling system functionality.
Have more questions? Visit your nearest RDO Equipment Co. location or call:1-800-834-0187.