Anticipating Every Turn: Fleet Maintenance Tips for Medium & Heavy-Duty Trucks

Whether your fleet includes box trucks running local routes or 18-wheelers hauling freight across the country, one thing is certain: maintenance isn’t optional—it’s essential. And at Lawson Products, we’re here to help you stay ahead—before you need it.

We’re not just a supplier. We’re an extension of your team. That means offering trusted protection through reliable products, practical advice, and proactive support that keeps your trucks moving and your crews safe.

Fleet Maintenance Isn’t Seasonal—It’s Strategic

Truck maintenance isn’t something to only ramp up when the weather changes. While extreme heat and cold present specific challenges, the real key is consistency. Staying on top of fleet maintenance year-round helps prevent avoidable issues before they turn into costly breakdowns—or worse. It saves time, protects lives, and keeps your team operating at full strength.

Why Consistency Matters—Daily, Monthly & Random Inspections

The Federal Motor Carrier Safety Administration (FMCSA) and Department of Transportation (DOT) require carriers to maintain a regular inspection and maintenance program that includes:

•  Daily pre-trip and post-trip inspections by the driver

•  Systematic, documented inspections done regularly (usually every 30–90 days)

•  Annual inspections by qualified technicians

•  Unannounced roadside inspections at weigh stations or by law enforcement

Random roadside checks can happen anytime—and violations often result from missed basics like lighting, brakes, or visible fluid leaks. Daily habits and monthly routines reduce the risk of a red tag or out-of-service order.

Your Year-Round Fleet Maintenance Checklist

Here’s how to break down inspection frequency for each critical area:

1. Wiper Blades – Check daily

Wiper blades are easy to forget—until the weather turns. Whether it’s a summer downpour or winter sleet, clear visibility is non-negotiable. Clear visibility is a top safety priority and part of every DOT pre-trip inspection. Blades should be inspected after every route and replaced if streaking or squeaking is visible. Replace them regularly to keep your drivers safe and inspection-ready.

2. Lighting & Electrical – Check daily; inspect monthly

From clearance lights to brake lights, reliable lighting is essential for both safety and DOT compliance. But with all the bumps, weather, and wear that come with the road, issues like vibration, corrosion, and tired wiring can sneak up fast.

A quick daily walk-around helps catch burned-out bulbs before they become a problem, and a more thorough monthly check can spot issues with wiring, sockets, or weatherproof seals. Stay ahead of downtime—and stay visible out there.

3. Cooling Systems & Rubber Components – Inspect Monthly

Your cooling system works hard—especially in summer heat and stop-and-go conditions. And while components like belts, hoses, and seals don’t always show immediate signs of failure, they’re some of the most common sources of unexpected downtime when neglected.

Rubber parts naturally degrade over time due to heat, vibration, and exposure to chemicals. Cracks, bulges, soft spots, or leaks can form quietly—then fail suddenly. That’s why it’s essential to do a thorough inspection at least monthly as part of your routine fleet maintenance.

Check:

•  Belts for fraying, glazing, or loss of tension

•  Hoses for cracks, swelling, or leaks at connection points

•  Seals and gaskets for hardening or signs of coolant seepage

If your fleet operates in extreme summer heat or cold winters, seasonal inspections are even more important. Rapid temperature swings put added stress on rubber components and can accelerate wear.

Pro tip: Stock a few common hose and belt sizes in your shop or service trucks, along with trusted sealants and leak detectors, so you’re never caught off guard.

4. Tire Pressure & Wheel Balance – Check daily; rotate monthly

Tires are one of the most critical—and most commonly cited—causes of out-of-service violations. But the good news? With a solid tire maintenance routine, most issues can be prevented before they slow you down.

Drivers should check tire pressure with a tire pressure gauge and inspect tread wear as part of their daily walk-around. Low PSI doesn’t just reduce fuel efficiency—it can lead to dangerous blowouts that put your driver, cargo, and uptime at risk. Uneven wear can also signal alignment issues or the need for rotation.

On a weekly or monthly basis, be sure to inspect tire balance and overall condition. Wheel weights play a key role in maintaining balance—helping prevent vibrations that can lead to premature tire wear, driver fatigue, and even suspension damage. Properly balanced tires improve ride quality, extend lifespan, and keep your rig steady on the road. 

Equipping your crew with reliable tire tools gives them the confidence to spot early warning signs—before they become costly problems. A proactive tire maintenance plan doesn’t just keep your fleet compliant—it helps you avoid roadside breakdowns, protect your investment, and keep deliveries on schedule.

5. Lubrication & Fluids – Grease Weekly, Check Fluids Daily

Staying on top of grease and fluid maintenance is one of the smartest ways to prevent breakdowns and protect your fleet investment.

Daily checks should include oil, coolant, and DEF fluid levels. These are the lifeblood of your engines—running low can quickly lead to overheating, loss of power, and even major engine damage. A quick fluid check during pre-trip walk-arounds helps catch problems early and keeps your vehicles road-ready.

Weekly or monthly, it’s just as important to take care of grease points. Suspension, steering, drivetrain, and other high-wear components rely on proper lubrication to avoid metal-on-metal contact that can lead to premature wear or failure. Make it part of your PM routine to grease all zerk fittings regularly.

To make the job easier and more effective:

•  Use a grease pump kit to streamline re-lubing and reduce waste.

•  Use a grease like Leverage Ultra Premium Lithium Complex Grease for high-load, high-temp conditions—it won’t wash out or break down under summer heat. 

•  Train your team to spot signs of grease failure like squeaks, vibration, or visible wear.

Pro tip: Even the best greases and fluids won’t do their job if they’re contaminated or neglected. Store them properly, label everything clearly, and keep your crew in the loop with a simple maintenance checklist.

6. Air Brake Systems – Check Daily, Test Weekly

Air brake performance is non-negotiable when it comes to driver safety and DOT compliance. Before every route, drivers must perform an air pressure test—a quick but essential step to catch leaks or malfunctions early. These systems are your first line of defense on the road, especially under heavy loads.

During weekly or monthly inspections, technicians should take a closer look for cracked lines, slow air build-up, worn components, or audible air leaks. Even small issues in air lines or chambers can lead to costly out-of-service violations or dangerous brake failure.

To keep systems road-ready:

•  Use air brake fittings that are built to withstand vibration and corrosion.

•  Check for proper sealing and thread engagement at every connection.

•  Document and tag any worn or mismatched parts to prevent repeat issues.

Proactive checks help prevent sudden failures, keeping your fleet moving safely and efficiently.

7. Battery Health – Inspect Monthly

Heat, road vibration, and poor cable connections can dramatically shorten battery life—especially in the summer months. That’s why monthly battery inspections should be a routine part of your fleet’s maintenance schedule.

Check for:

•  Loose or corroded terminals

•  Swollen or leaking batteries

•  Damaged or frayed cables

•  Improper mounting, which can cause damaging vibration

Equipping your team with reliable battery testers and fillers makes it easy to spot early signs of trouble and keep electrolyte levels in check. A healthy battery system means more reliable starts, fewer roadside jump calls, and less downtime in the shop.

8. Cords & Connectors – Inspect Daily During Hookups

Every trailer hookup is a chance to prevent downtime. Tractor-trailer cords and connectors should be checked daily for bent pins, loose plugs, corrosion, or signs of wear.

Electrical issues in trailer connections are a common cause of FMCSA violations—and often preventable with a quick inspection during pre-trip walk-arounds.

•  Keep an eye out for:

•  Broken grommets

•  Frayed insulation

•  Rust or moisture at terminals

•  Excessively tight or slack cable tension

Replacing worn components with high-durability electrical connectors can prevent shorts, lighting malfunctions, and unnecessary repair calls down the line. Don’t let a faulty connection bring your route to a halt.[KD9] 

9. Leak Detection – Check Weekly or During PMs

Leaks don’t always leave a puddle behind. Whether it’s your cooling system, power steering, or A/C, some of the most damaging leaks go unnoticed—until it’s too late.

Include leak checks in your weekly or scheduled PMs, especially in systems under pressure or with older seals. Use leak detection kits or dyes to identify pinhole leaks and hairline cracks before they cause major failures.

Quick tip: Train techs to look for residue or grime buildup around joints and seals, which could signal a slow leak. Prevention now can save hours in diagnostics later—and help avoid roadside repair calls that slow down delivery times.

10. Cabin & Surface Care – Clean Weekly or As Needed

A clean cab isn’t just about appearance—it’s about safety, comfort, and pride in your fleet. Regular cleaning reduces driver distractions, allergen buildup, and trip fatigue, especially during long summer hauls.

Encourage your team to:

•  Do weekly wipe-downs of steering wheels, dashboards, and controls.

•  Keep floors and windows free of dust, grease, and spills.

•  Use high-quality cleaning products that won’t leave streaks or residue.

For fast, effective cleanups, stock your fleet with:

•  FalconGrip® Nitrile Gloves for protection during maintenance or clean-up tasks

•  Universal sorbent pads for oil, grease, or fluid spills in the cab or cargo area

•  Drummond™ Ogle Glass Cleaner for a clear view, even in bright summer glare

A clean, well-maintained cab isn’t just better for morale—it’s a safer workspace for every mile ahead.

Pro Tip: Keep a Maintenance Log

FMCSA guidelines require fleets to document all maintenance and inspection activity. Ensure your team is logging:

•  Daily pre- and post-trip inspection reports

•  Dates of oil changes, tire rotations, brake tests, and system checks

•  Any part replacements, adjustments, or repairs

Built for the Road Ahead

At Lawson, we don’t wait for problems—we help prevent them. Whether you use our managed inventory services or prefer a lighter touch with customer managed inventory or online shopping, we’ll help you keep the right parts in reach, all year long.

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