Coolant transfers away much of the heat produced by an engine, preventing overheating. If you run a commercial fleet, maintaining proper coolant levels will protect your vehicles and minimize the need for truck service. Here's what to know to keep your investments in top shape.

How to Prevent Contamination

Contamination can occur when different coolants are mixed. Since municipal water may contain microscopic particles, adding it to coolant can also lead to problems. Affected products usually produce acids or scaling, which decrease their effectiveness and could lead to engine damage and overheating. A few common signs of these issues include brown coloring and visible debris. 

Contamination often occurs when drivers top off fluid levels on the road, so educate your team on the importance of using the right products and avoiding mixing. If there are multiple types of vehicles in your fleet, they might each require a different coolant. Label stored fluid tanks so team members know which products are recommended for what trucks. While extended-life coolants can last over 300,000 miles, some vehicles require organic-acid (OAT) or nitrate organic-acid technology. When in doubt, technicians should use nitrate-free OAT products, which prevent corrosion and are compatible with all cooling systems.

More Coolant Upkeep Tips

Generally, the coolant-to-water ratio for commercial trucks should be 50/50. Too few additives won’t properly cool the engine, while not diluting coolant can increase deposit levels and clog auto systems.

Have the fleet's fluids checked every six months to ensure they remain at this level. Mechanics should use coolant test strips during each oil change to verify the chemical concentration. Instruct them to only use water that's been tested for contaminants to flush out the cooling system and dilute products as needed. Preventive maintenance will keep your fleet running smoothly.


If you require truck services, turn to Northwest Truck Repair of Kalispell, MT. Having served the area since 1972, their team understands that getting back on the road quickly is essential for your livelihood. As such, you can expect efficient work. They only use auto parts from trusted brands, including Cummins® and Baldwin®. Visit them online to learn more about their truck services, or call (406) 755-9762 to schedule an appointment.