When it comes to heavy-duty truck maintenance, most operators stay focused on the big-ticket items—oil changes, brakes, tires, and scheduled PM services. While these are critical, many costly breakdowns can actually start with smaller components that are easy to overlook.
These often-forgotten maintenance items may not cause immediate issues, but neglecting them can lead to reduced performance, unexpected downtime, and expensive repairs. In this edition of the Maintenance Monthly we are highlighting some of the most overlooked items on heavy-duty trucks and why they matter.
The air system supports braking, suspension, and other critical functions, yet many of its components don’t receive attention until a problem occurs. Air dryers, valves, and hoses can collect moisture over time, leading to corrosion, frozen air lines, and reduced braking efficiency.
Routine inspections and replacing air dryer cartridges at recommended intervals help keep moisture out of the system and improve performance year-round.
With today’s trucks relying heavily on electronic systems, electrical issues are increasingly common—and often misdiagnosed. Loose or corroded battery terminals, grounding points, and wiring connections can trigger warning lights, sensor faults, or intermittent issues that are difficult to narrow down.
Checking electrical connections during routine maintenance can prevent unnecessary diagnostics and keep systems communicating properly.
Cooling system maintenance often stops at checking coolant levels, but hoses and clamps deserve regular inspection as well. Heat, pressure, and age can weaken hoses even if no leaks are visible.
A failing hose or clamp can cause sudden coolant loss and overheating, potentially leading to engine damage. Inspecting hoses for softness, cracking, or bulging—and replacing them proactively—helps avoid unexpected breakdowns.
Driveline components are easy to forget because they’re out of sight, but they play a key role in delivering power smoothly. U-joints and carrier bearings require proper lubrication and inspection to prevent vibration and premature wear.
Neglecting driveline maintenance can lead to costly failures that could have been avoided with regular greasing during PM services.
Suspension systems absorb constant stress from heavy loads and rough road conditions. While shocks and airbags are often checked, smaller components like bushings and mounts are frequently overlooked.
Worn bushings can cause uneven tire wear, poor handling, and added stress on suspension components. Catching wear early helps maintain ride quality and reduces long-term repair costs.
Regularly checking and torquing suspension components is also important, as vibration can cause hardware to loosen over time. Proper torque helps maintain alignment, reduce uneven tire wear, and prevent premature suspension damage.
Modern emissions systems rely on sensors to monitor performance and maintain compliance. When sensors or related wiring are damaged or contaminated, warning lights, regens, or engine derates can occur.
Regular inspections of sensors and wiring can help prevent unexpected downtime and keep emissions systems functioning properly.
Greasing is one of the simplest maintenance tasks—and one of the most commonly missed. Skipped grease points on steering and suspension components accelerate wear and shorten component life.
Following manufacturer-recommended lubrication intervals helps reduce friction, improve handling, and extend the life of critical components.
Overlooked maintenance items rarely cause immediate failures, but they often lead to bigger problems over time. A loose connection or worn hose can quickly turn into lost uptime and higher repair costs. Taking a proactive approach and addressing these commonly missed areas during routine service helps improve reliability, extend vehicle life, and protect your investment.
Have any questions? Contact your local Kenworth Of Pennsylvania Service Department to learn more today!