The 5 most common semi-truck breakdowns (and how to prevent them)

Roadside truck breakdowns aren’t just an inconvenience; they’re a significant disruption of fleet operations, impacting costs, driver safety, truck downtime operational efficiency and even customer satisfaction. For fleet managers, truck breakdowns translate to increased costs in the way of towing fees, emergency repairs and replacement parts. Delivery delays and penalties can also damage a company’s reputation and lead to further financial challenges.

For drivers, breakdowns mean lost income, as they miss out on pay due to downtime, and safety risks, as they deal with the dangers being stranded on the road. Plus, these stresses are time-consuming for drivers, decreasing morale and dramatically impacting turnover rates.

That’s why we recently partnered with FreightWaves to explore the impact of roadside breakdowns on fleets in our new white paper: “How do roadside breakdowns impact efficiency and retention.” This research uncovered some compelling insights, with a significant 37% of survey respondents reporting fleet truck breakdown costs ranging from $1,000 to $2,500, as well as a major impact on overall fleet performance and driver retention. While breakdowns are an inevitable part of trucking, understanding their most common causes is the first step toward prevention and mitigation.

Five most common causes of semi-truck breakdowns and how to apply proactive maintenance strategies to avoid them:

1. Tire troubles: A leading cause of fleet truck breakdowns

Tire issues are arguably the most common culprit behind roadside breakdowns. From sudden blowouts to slow leaks and tread separation, tire problems can bring a heavy-duty vehicle to a screeching halt. A flat or blown tire immediately renders the vehicle inoperable, leading to significant downtime. This translates directly to delayed deliveries, missed appointments and potentially spoiled cargo, especially for temperature-sensitive goods. The ripple effect can disrupt dispatch schedules and require re-routing other vehicles to pick up the slack.

A tire blowout, particularly at highway speeds, can cause a driver to lose control of the vehicle, leading to a serious accident involving other motorists. Even a gradual flat tire can compromise braking and steering, increasing the risk of a collision. Repairing a tire on the roadside also exposes drivers to the dangers of passing traffic. According to the Federal Motor Carrier Safety Administration (FMCSA), tire blowouts cause approximately 8,000 trucking accidents annually in the United States. 

To prevent semi-truck tire blowouts, regular, proactive maintenance inspections are crucial. Tire Pressure Monitoring Systems (TPMS) provide real-time tire pressure information, alerting drivers to any deviations from optimal levels, as maintaining correct tire pressure as recommended by the manufacturer, is essential for safety and longevity. Drivers should also conduct thorough pre-trip and post-trip inspections to identify any signs of damage, wear or underinflation (underinflated tires are prone to blowouts and reduced fuel efficiency).

Proper tire rotation and balancing also extend tire life and prevent uneven wear. And finally, investing in reputable brands known for their durability and reliability can also reduce the risk of semi-truck tire blowouts, contributing to overall fleet maintenance.

2. Engine and powertrain malfunctions: The heart of the problem

Issues with the engine or powertrain system are often complex and can lead to immediate and complete vehicle failure. These can range from minor sensor malfunctions to catastrophic engine failure. An engine or powertrain breakdown means the vehicle is completely immobilized. This results in extended downtime, often requiring towing to a repair facility and costly, lengthy repairs. The time out of service can be substantial, leading to major schedule disruptions and significant revenue loss. 

A sudden loss of power on a highway or busy road presents an immediate safety hazard, especially if the vehicle cannot quickly move to a safe location. This can lead to rear-end collisions or other multi-vehicle accidents. Exhaust system leaks can also pose a risk of carbon monoxide poisoning for the driver.

Our report found that 44% of fleets anticipate downtimes of 6 hours or more due to breakdowns, with 16% facing disruptions exceeding 24 hours. Adhering to a strict preventive maintenance schedule for engine components is vital. This includes regular oil changes, filter replacements (oil, air, fuel), cooling system checks, and monitoring engine diagnostics for any warning signs. Addressing dashboard warning lights promptly, even if they seem minor, can prevent a small issue from escalating into a major breakdown. Regular tune-ups and inspections of belts, hoses, and fluid levels are also crucial.

3. Brake system failures: A critical threat to fleet safety

The brake system is critical for fleet safety. Any malfunction, from air leaks to worn pads or contaminated fluid, can compromise a truck's ability to stop effectively. A brake system failure immediately renders the vehicle unsafe to operate. Depending on the severity, it might require immediate roadside assistance or a slow, careful drive to the nearest service center. Even minor brake issues can lead to reduced efficiency as drivers become more cautious, impacting route times.

This is arguably the most dangerous type of breakdown, making effective, routine maintenance management vital. A compromised braking system drastically increases the risk of collisions, especially when hauling heavy loads or navigating downhill grades. Loss of braking power can lead to catastrophic accidents, causing severe injuries or fatalities. The FMCSA identifies brakes as among the most impactful elements of truck crashes, with an estimated 30% of truck accidents caused by brake failure.

Regular and thorough brake inspections and strict truck maintenance are non-negotiable. This involves checking brake pads, shoes, drums, rotors, air lines, and fluid levels. It's crucial to address any signs of wear, such as squealing, grinding noises, or a spongy brake pedal, immediately. Proper adjustment of slack adjusters for air brakes and timely replacement of worn components are essential for maintaining optimal braking performance.

4. Electrical system issues: The hidden disruptor

Modern commercial vehicle fleets rely heavily on complex electrical systems, and even minor faults can lead to significant operational problems. These can include issues with the battery, alternator, starter, or wiring. Electrical problems can manifest in various ways, from a vehicle failing to start to sudden loss of power while driving, or malfunctions of critical components like lights, wipers, or dashboard instruments – causing a wide range of problems, from minor inconveniences to major fleet truck breakdowns.

A dead battery or faulty starter can leave a driver stranded in an unsafe location. Loss of headlights or taillights at night, or non-functional wipers during inclement weather, significantly reduces visibility and increases the risk of accidents. Faulty wiring can also lead to vehicle fires.

Regular inspection of battery terminals for corrosion, checking battery charge levels, and ensuring proper functioning of the alternator and starter motor are essential. Maintaining a healthy battery is essential for the proper functioning of the entire electrical system, thus improving fleet uptime and reducing truck repair needs. Keeping wiring harnesses free from corrosion and promptly addressing any blown fuses or flickering lights can prevent more significant electrical issues.

5. Cooling system overheating: A key focus for proactive maintenance

An overheating engine, usually caused by issues within the cooling system (e.g., low coolant, faulty thermostat, leaky hose, or a malfunctioning fan), can lead to severe engine damage if not addressed quickly. An overheating engine requires immediate shutdown to prevent permanent damage. This leads to unexpected roadside stops and significant downtime while the engine cools and the issue is diagnosed and repaired. Severe overheating can result in complete truck breakdowns with costly engine rebuilds or replacements, leading to prolonged vehicle downtime and substantial financial outlays.

While not as immediately dangerous as something like brake failure, steam or hot fluids can pose a burn risk during an attempted roadside inspection. More importantly, operating an overheated engine can lead to total engine failure, potentially seizing on the road and creating a hazard for other vehicles.

Inspecting hoses and clamps for leaks or cracks, ensuring the radiator is clear of debris, and verifying the proper operation of the thermostat and cooling fan can prevent overheating. Flushing the cooling system periodically and replacing coolant according to manufacturer recommendations also helps maintain its effectiveness.

The role of technology in preventative maintenance and fleet truck repairs

While semi-truck breakdowns may seem inevitable, purpose-built technology solutions offer powerful ways to mitigate their frequency and impact on fleet operations.

When paired with modern telematics solutions, Trimble TMT Fleet Maintenance tracks vehicle health in real-time, using data to predict potential failures before they occur and facilitate preventative maintenance. This proactive approach significantly reduces the likelihood of breakdowns, thereby minimizing downtime and extending vehicles’ lifespan. By analyzing data such as engine performance, component wear and operation conditions, these systems can identify patterns and predict when a component is likely to fail.

These systems also monitor critical parameters such as tire pressure, engine temperature and brake health. When a parameter deviates from the norm, the system can send immediate alerts, allowing for timeline intervention. This enables fleet managers to take action, preventing minor issues from escalating into major problems. Real-time data also provides valuable insights into vehicle performance, allowing for more informed maintenance management decisions and ultimately, improved fleet uptime.

But even with the best preventative efforts, breakdowns can still happen. TMT Road Call, a TMT Fleet Maintenance module designed to assist in the resolution of breakdowns, quickly connects dispatchers and drivers with service providers, expedites the repairs and minimizes vehicle downtime.

According to our white paper on roadside breakdowns, 68% of fleets take action within 30 minutes of a vehicle breakdown, but having a system like TMT Road Call in place can make that response even faster and more efficient. This not only reduces fleet downtime but also improves driver safety and satisfaction. Learn more about how fleets can adapt to unexpected breakdowns.

By understanding the common causes of semi-truck breakdowns and leveraging technology to prevent them, fleets can significantly improve operational efficiency, reduce costs and enhance driver satisfaction. Investing in preventive maintenance and utilizing advanced technologies is no longer a luxury but a necessity for fleets looking to stay competitive in today's demanding transportation industry.

Combat the most common semi-truck breakdowns with Trimble technology solutions

Fleet truck breakdowns can disrupt operations and lead to costly delays, but Trimble offers innovative tools to keep your fleet running smoothly. Our advanced diagnostic systems provide real-time insights into vehicle health, allowing you to proactively address maintenance issues before they become major problems. With Trimble's predictive analytics, you can optimize your maintenance schedules and reduce unexpected downtime. 

Our solutions enhance driver safety, efficiency and connectivity, ensuring that your fleet operates at peak performance. Want to learn how you can start mitigating the impact of breakdowns with proactive, preventative maintenance solutions like TMT Fleet Maintenance and TMT Road Call? Contact our team.