By Tharran Gaines

Like the engines they maintain, the cooling systems on today’s farm machinery have changed dramatically over the past few years. Even though modern larger diesel engines – often equipped with exhaust gas recirculation systems to help meet emissions standards – run hotter than engines of the past, electronic sensors and control systems automatically deregulate the unit when it begins to overheat. That certainly doesn’t diminish the need to properly maintain the cooling system, however.

One of the most obvious steps is to keep the radiator and any cooling units (air conditioner evaporator, hydraulic fluid cooling uni) positioned in front of it clear of dirt and debris. But don’t use water for this job unless everything is allowed to dry before you head to the field. To do otherwise could result in caking up cooling fins with mud and chaff. Instead, use compressed air to blow out the debris from the back side.

At least once a week (and more often when putting in long hours in the field), check coolant levels. Also, test coolant quality regularly as outlined in the machine’s service manual. While most antifreeze formulations contain approximately 95% ethylene glycol, the full solution also has water and an additive package designed to prevent rust, scale, and corrosion.

Products formulated for diesel engines contain nitrate or another type of additive to coat wet engine sleeves and protect to against cavitation and the resulting erosion. Other additives serve to protect copper, brass, and aluminum components and to buffer acids formed by the breakdown of glycol. These additives wear out or are depleted as the coolant ages.

“Equipment owners have a couple options when it comes to evaluating the coolant quality,” says Randy Aronson, service manager at Dean Machinery, Chillicothe, Missouri. “A number of dealers can run a coolant analysis, which not only determines coolant condition, but also identifies any other problems that can show up in the cooling system.”

Most dealers sell paper test strips that can be used to home-test both the freeze level of the coolant and the condition of the coolant additive.

Always Go With The Original Fluid Package

If a system contains an extended-life coolant, you can generally renew it with a supplemental coolant additive (SCA) package. Just be sure the antifreeze type and additives are compatible. Some formulations have fundamentally different chemical compositions, particularly when you compare extended-life, organic-acid coolants with fully formulated coolants that were predominant 15 to 20 years ago. So it’s best to match what is already in the system or to pick an antifreeze type for complete replacement and stick with it.