When it comes to keeping your fleet on the road and out of the red, skipping preventive maintenance is never going to work. In fact, putting off basic upkeep could cost your operation thousands in downtime, major repairs, and even fines. 

We’ve gone through key tasks you shouldn’t ignore, the cost of neglect, and what you should be doing instead.

Engine Oil and Fluid Changes

Let’s start with the basics: engine oil. Your engine relies on oil to lubricate, cool, and clean internal components. Skip oil changes, and you'll start seeing increased engine wear, overheating, and eventual breakdowns. 

Diesel engines, especially those under constant load, generate intense heat and pressure. Dirty oil loses its viscosity, fails to lubricate, and turns into sludge faster than you can say “breakdown.”

And it’s not just engines. Transmission fluid, coolant, and gear oil all play crucial roles in keeping your drivetrain smooth and cool. If you ignore these, you're inviting overheating, gear slippage, and catastrophic failure.

Action Tip

Follow OEM schedules. Track oil life by mileage and engine hours. Use high-quality fluids and monitor for discoloration or a burnt smell.

Brake Inspections

Brake components don’t last forever, especially not in commercial rigs that haul tens of thousands of pounds. Slack adjusters, brake shoes, and air lines wear down over time. Let these go unchecked, and you’re putting drivers, cargo, and everyone on the road at risk.

Even worse, brake failures are a top cause of DOT violations. That’s a one-way ticket to fines, impoundments, and skyrocketing insurance.

What to Look For

• Uneven wear on brake shoes
• Leaky or cracked air lines
• Slow air build-up time
• Overheating or smoking wheel ends

Action Tip

Schedule monthly brake checks, including testing your air compressor, air dryer, and S-cam mechanism.

Cooling System Neglect

Your cooling system prevents warping, seizing, and blowing gaskets. Coolant breaks down over time, and when it does, it can no longer absorb and disperse radiant heat efficiently.

Ignoring radiator flushes, thermostat testing, and fan clutch inspections can turn your engine into a glorified furnace. And trust us, replacing a blown head gasket or cracked block isn’t a quick fix; it’s a $10,000+ mistake.

Action Tip

Flush coolant every 24 months or as per OEM. Inspect hoses and clamps for leaks. Test the fan clutch function, especially in summer heat.

Tire Maintenance

Bald or unevenly worn tires are unsafe. Improper tire pressure reduces fuel economy, increases blowout risk, and chews through treads faster than necessary. If one tire goes, you're also risking damage to axle shafts, bearings, and suspension components.

Let’s not forget: a single blowout on the highway can damage your trailer, slow down your delivery, and trigger roadside repair fees that could buy you a brand-new set of tires.

Action Tip

Perform weekly pressure checks. Rotate tires regularly. Keep an eye on wheel bearing heat, especially on long hauls.

Transmission Fluid

Skipping transmission service is another surefire way to drain your budget. Low or dirty transmission fluid leads to gear slipping, clunky shifting, and even overheating. Rebuilding a transmission is a five-figure endeavor and often means multiple days off the road.

Action Tip

Use dipsticks or digital sensors to monitor fluid levels and color. Burnt smell or brown coloration = flush it now. Don’t wait for a tow bill to tell you it’s time.

Aftertreatment Systems

Modern diesel trucks rely on aftertreatment systems like DPF, SCR, and EGR to meet emissions regulations. Neglecting these can cause clogging, force regeneration failures, and ultimately trigger check engine lights and power derates. Letting DEF tanks run dry or ignoring DPF regeneration schedules is a fast track to being parked on the shoulder.

It’s not just breakdowns you need to worry about when it comes to aftertreatment systems. If these aren’t working correctly, you can breach emissions regulations. And with each breach coming with the possibility of a fine of over $45,000, you can’t afford to risk it.

Action Tip

Check DEF levels regularly. Run parked regens when prompted. Schedule cleaning intervals for DPF filters. Always monitor for NOx sensor or EGR valve faults.

Suspension and Bearings

When shock absorbers wear out or leaf springs crack, you’re inviting uneven load stress, tire wear, and frame damage. Meanwhile, dry bearings can overheat, seize up, and cause wheel-offs. That’s not just a bill—it’s a lawsuit waiting to happen.

Action Tip

Grease wheel bearings regularly and monitor for excessive heat or noise. Inspect suspension components monthly for signs of stress, corrosion, or fatigue.

Skipping Preventive Maintenance Is a Strategic Mistake

In a town like Oskaloosa, where every truck on the road is part of someone’s livelihood, skipping maintenance is irresponsible. You don’t need a crystal ball to predict the future here. Preventive maintenance isn’t an expense; it’s an investment. One that keeps your trucks rolling and your bottom line in the black.

Final Thoughts

If you want your fleet to keep running smoothly and avoid eye-watering repair bills, preventive maintenance isn’t optional—it’s mission-critical. Stay ahead of problems, and they won’t have a chance to become disasters. 

Whether it’s keeping those fluids topped off or staying on top of brake wear, small actions today prevent big breakdowns tomorrow.