Focused on coolant

Feb. 18, 2015
Manager: Bob Slaughter
Title: Director of fleet maintenance
Company: Murphy Brown Trucking
Operation: Private fleet running 300 tractors pulling 430 livestock and feed tank trailers Problem:

Manager: Bob Slaughter
Title: Director of fleet maintenance
Company: Murphy Brown Trucking
Operation: Private fleet running 300 tractors pulling 430 livestock and feed tank trailers


Keeping trucks up and running is job number one at any fleet, yet the stakes are much higher when that fleet hauls livestock. Murphy Brown Trucking is that fleet, hauling live hogs and feed for Warsaw, NC-based Murphy Brown LLC. The company includes 450 company-owned farms and 2,000 contracted farmers and growers in 12 states, producing some 16 million hogs every year for Smithfield Foods.

Murphy Brown Trucking tackles the transport of hogs and feed with a private fleet of 300 day cab tractors and 300 livestock trailers plus 130 or so feed tank trailers. Drivers typically operate within 100 mi. of their domicile so they are usually home every night.

It falls to Bob Slaughter and his team of 40 technicians scattered among six shops to keep all that equipment up and running.

Slaughter believes that the basic “blocking and tackling” of preventive maintenance (PM) is critical to keeping downtime to a minimum and preserving the resale value of equipment.

“Today’s technician is not always interested in focusing on PM work; they want to get into more interesting things like rebuilding engines,” he explains. “But it’s the basics that pay the bills.”


One of the basics that Slaughter and his maintenance team focus on is engine coolant. It is checked for every truck at every oil change, which is usually anywhere between 25,000 and 30,000 mi. “We make coolant checks an important part of our PM process,” Slaughter explains. “My philosophy is to invest in a premium long-life coolant at the start and then check it regularly to make sure the pH level is the proper balance, for starters.”

Susan Thompson, product information team manager and technical service manager at WIX Filters, stresses that the type of engine coolant in use by a fleet will dictate its PM strategy to a large degree.

In general, engine coolants are either ethylene glycol or propylene glycol based, she explains, with the key difference being the type of chemical additive package within the coolant.

As time goes on, some chemical additives get “used up” and need to be replaced. However, newer organic acid technology (OAT) additives require that the coolant itself be completely replaced—usually at a 150,000-mi. interval—once the additives get used up.

“Newer trucks typically come factory-filled with OAT engine coolant. But at the end of the day, fleets need to do what they are most comfortable with and what’s best for their shop practices,”  Thompson says.

Above all, though, she emphasizes that taking a holistic view of the coolant system—not just the coolant itself—is critical within a truck PM strategy.

“You need to look at the environment within which a truck works, the temperature variation it’s exposed to, and the condition of the equipment overall as well as the coolant system,” Thompson says. “A properly maintained coolant system lowers the freeze point and raises the boiling point, protecting the engine across all seasons.”

Murphy’s Slaughter points out that the different operating conditions of his fleet’s trucks necessitate a more watchful eye on engine coolant.

“Our feed delivery trucks are PTO [power take-off] equipment and so the engine runs more; we also trade them out at about the five-year mark,” he notes. “We keep our livestock tractors for seven years. And we get top dollar when we sell them, too, because we care for them well.”

Slaughter adds that improper coolants and inadequate cooling system maintenance can result in overheating engines and “pitting” in piston linings if the coolant leaks into the engine oil, adding up to some very expensive repairs.

“While coolant checks can be things people tend to ignore, coolant problems can lead to a $30,000 engine repair bill,” he explains. “That’s something you can’t ignore.”

About the Author

Sean Kilcarr | Editor in Chief

Sean previously reported and commented on trends affecting the many different strata of the trucking industry. Also be sure to visit Sean's blog Trucks at Work where he offers analysis on a variety of different topics inside the trucking industry.

Voice your opinion!

To join the conversation, and become an exclusive member of FleetOwner, create an account today!

Sponsored Recommendations

Leveraging telematics to get the most from insurance

Fleet owners are quickly adopting telematics as part of their risk mitigation strategy. Here’s why.

Reliable EV Charging Solution for Last-Mile Delivery Fleets

Selecting the right EV charging infrastructure and the right partner to best solve your needs are critical. Learn which solution PepsiCo is choosing to power their fleet and help...

Overcoming Common Roadblocks Associated with Fleet Electrification at Scale

Fleets in the United States, are increasingly transitioning from internal combustion engine vehicles to electric vehicles. While this shift presents challenges, there are strategies...

Report: The 2024 State of Heavy-Duty Repair

From capitalizing on the latest revenue trends to implementing strategic financial planning—this report serves as a roadmap for navigating the challenges and opportunities of ...