General Truck Repair
April 11, 2022

Signs That Your 18-Wheeler Needs Maintenance Service

Regardless of whether you’re an owner-operator or a manager of a multi-vehicle fleet, your, 18-wheelers are a critical part of your business and livelihood. While different models of trucks have different service requirements, there are a few key maintenance indicators that remain the same across different brands.

18 wheeler maintenance

Regardless of whether you’re an owner-operator or a manager of a multi-vehicle fleet, your, 18-wheelers are a critical part of your business and livelihood.  You rely on your heavy-duty truck to haul cargo over hundreds of miles.  From time to time though, your truck is going to need maintenance, and if you are alert to them, there are some signs that it’s time to book your service. While different models of trucks have different service requirements, there are a few key maintenance indicators that remain the same across different brands.

Warning lights on the dashboard 

Your truck’s dashboard's maintenance-reminder lights are something that should never be ignored. The following is a list of typical semi-truck dashboard lights:

  • Check engine 
  • Engine fuel pressure 
  • Coolant level
  • Oil level
  • Tire pressure
  • Battery warning
  • Indications for seatbelts and airbags truck maintenance for semis

While certain symbols are common to all heavy-duty trucks, there are a few differences in how warning lights are shown. Your truck’s owner's handbook is a valuable resource for understanding the meaning of specific lights in your 18-wheeler.

High mileage 

Most truck-makers advise servicing your heavy-duty truck after a certain number of miles. There are often two criteria based on "regular" or "severe" service schedules. According to AAA, heavy-duty trucks with the following features are subject to strict servicing schedules:

  • Primarily short journeys (5 miles or less)
  • Conditions that are very dusty, hot, or chilly
  • Driving that is always in motion
  • Regularly carrying heavy loads

That final one includes truck drivers in a strict servicing schedule for a good cause. Truck accidents may be horrifying events with several fatalities and significant property damage. Maintaining a tight rein on maintenance may prevent parts from deteriorating and failing since technicians can identify the problems much earlier.

One of the best examples of different heavy-duty truck thresholds is the time between oil changes. Some manufacturers advise changing the oil every 3,000 miles for heavy-duty trucks with rigorous maintenance regimens since it might be challenging to determine oil conditions by color. Although some claim that full-synthetic motor oil may last up to 15,000 miles, most current engine oil manufacturers estimate that the oil will last between 5,000 and 7,500 miles (although your oil filter won't likely thank you).

Loss of fluids 

Speaking of oil changes, it’s important to pay attention to all your 18-wheeler’s essential fluids.  

Other indications that your heavy-duty truck urgently requires repair include leaking engine coolant, gearbox, power steering, compressed air, and power steering fluid. It's possible that your engine's power will be significantly reduced, and you could even face stalling and other serious problems if these fluids are not maintained.

Your heavy-duty truck will consume more fuel if there is an oil leak, and the additional friction on the mechanical components may create serious engine problems. Your heavy-duty truck may have longer stopping distances and be less able to maneuver quickly if there is a pressurized air leak. At high speeds, this might lead to hazardous circumstances.

Signs of a transmission fluid leak include elevated engine temperature, complex gear changes, and higher fuel use. Both an automatic and a manual gearbox will struggle to start if there is no fluid. Wear on the pump belt, and a loss of steering control are two symptoms of a hydraulic fluid leak in the power steering system. The engine may overheat due to a coolant leak, increasing the frequency of coolant and antifreeze flushes. Before heading out on the road, be sure to check your fluid levels to minimize extra engine wear.

Worn out belts 

It could be time to inspect the engine belts if you hear chirps and squeals, suddenly lose system performance, or have a check engine light flashing at you. Serpentine belts, drive belts, and timing belts are the belts that are seen in an engine compartment the most often.

Serpentine belts regulate several parts, including the air conditioning compressor, power steering pump, water pump, crankshaft, and alternator.

Drive belts are serpentine belts that are specific to a system. Drive belts, also known as v-belts, may have two to three, while a serpentine belt is a single unit. The kind of belts you have depends on your truck’s engine.  

Timing belts control the "interference" engine that most modern heavy-duty trucks use. An interference engine indicates that since the engine's sections operate at close intervals, specific portions may prevent others from completing their tasks. To avoid this, timing belts synchronize the crankshaft and camshaft.

Due to the significance of these components, you should check them at every mechanical service. Fortunately, they all last about the same amount of time; it is advised that they be inspected every 60,000 miles and changed every 90,000.

High fuel consumption 

Low fuel efficiency is one indication that your heavy-duty truck requires repair. A semi-truck may get up to 11 miles per gallon on highways and 6 to 9 in cities, but if you are finding that you’re having to fill up frequently,  it may be time to bring your rig in for maintenance.
Most modern heavy-duty trucks have an electronic onboard computer (EOBC), and the dashboard will show you what your fuel consumption is. It’s important to keep a record of your average consumption so you can quickly identify any changes. .

Changes in exhaust color 

Any color of your exhaust fumes other than which can be an indicator of your truck needing maintenance.  The blue flame that emerges from the engine of a semi-truck, big rig, or eighteen-wheeler is water vapor that should be a thin, white tint.

There are other colors of smokes to think about. A thicker white-gray exhaust indicates a failing head gasket. You may have an oil leak if your exhaust is blue or gray. A blocked manifold, clogged engine air filter, or a broken fuel injection system are the most frequent causes of black exhaust. You will always need to fix the heavy-duty truck to prevent the engine from overheating and experiencing catastrophic damage.

Brake problems 

Brake problems are a pretty clear indicator that your heavy-duty truck requires servicing. Drum brakes and disk brakes are the two most popular types of brakes. In contrast to disk brakes, which may be located up front or in the back, drum brakes are often seen on semi-trucks and large rigs.

In any scenario, your heavy-duty truck may make a grinding noise when the brake pads are engaged, halt steering power to the wheels, accelerate, or stop on slopes. Your heavy-duty truck has to be inspected.

Final words 

If you notice one or more of these issues in your 18-wheeler, you need to understand that it's high time for maintenance. While keeping that in mind, you may proceed with care and ensure that you don't run into any issues. 

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