10 Commonly Missed Items During A Pre-Trip Inspection

semi truck on interstate

Pre-trip inspection’s are an essential part of every truck driver’s routine. It ensures the safety of both the driver and other road users by checking that the truck is in good working condition before hitting the road. However, even the most experienced drivers can sometimes overlook a few crucial points during their inspection. In this article, we’ll take a look at some of the most commonly missed points during a semi-truck pre-trip inspection, helping you avoid any potential trouble on the road ahead.

1. Brake Lines and Hoses

Brake lines and hoses are a critical component of your semi-truck’s braking system. When you hit the brake pedal, air from your reservoir is supplied to the brake valves and is then delivered to your brake chambers. The brake chamber then moves the pushrod to push on a slack adjuster. The end result forces the shoes against the drum, slowing or stopping the wheel. Unfortunately, these essential parts are often overlooked during pre-trip inspections. When checking your brake lines and hoses, make sure to:

  • Look for any signs of wear, cracks, or uneven wear.

  • Ensure that the lines and hoses are not leaking

  • Check for proper routing and secure connections

Taking the time to inspect your brake lines and hoses can prevent a potentially disastrous brake failure on the road.

2. Lug Nuts and Wheel Seals

Lug nuts and wheel seals may seem like minor parts of a semi-truck, but they are essential for ensuring the safety and stability of your vehicle. Missing or loose lug nuts can lead to wheel separation, which can have catastrophic consequences at high speeds. Additionally, damaged wheel seals can lead to premature bearing failure. To avoid these issues, always:

  • Inspect all lug nuts for tightness, shiny threads, or rust trails.

  • Look for any signs of oil or grease leakage around wheel seals

3. Exhaust System

The exhaust system is another commonly overlooked aspect of a semi-truck pre-trip inspection. An improperly functioning exhaust system can lead to dangerous fumes entering the cabin and environmental pollution. It’s essential to inspect the exhaust system for:

  • Cracks, holes, or rust in the pipes, mufflers, or other components

  • Loose or missing clamps, brackets, or hangers

  • Discoloration or excessive soot around the exhaust pipe, which could indicate a problem with the engine

4. Steering Components

A semi-truck’s steering system is crucial for the safe operation of the vehicle. Unfortunately, many drivers fail to give this system the attention it deserves during their pre-trip inspection. To ensure your steering system is in good working order:

  • Check for excessive play in the steering wheel

  • Inspect the steering gear box and linkage for signs of wear, leaks, or damage

  • Look for loose, bent, or damaged tie rods, pitman arms, and other steering components

5. Suspension System

Your semi-truck’s suspension system plays a vital role in providing a smooth and stable ride. A damaged or worn suspension can negatively affect handling, braking, and tire wear. During your pre-trip inspection, make sure to:

  • Look for cracked, broken, or missing leaf springs and spring hangers

  • Inspect airbags for leaks, damage, or improper inflation

  • Check for loose or worn bushings, pins, or U-bolts

6. Electrical System

Your truck’s electrical system powers everything from your headlights and turn signals to your engine’s ignition system. A malfunctioning electrical system can lead to a variety of issues, including engine problems, lighting failures, or even a fire. To prevent these problems, always:

  • Inspect all wiring harnesses for signs of wear, damage, or chafing

  • Check for loose or corroded battery terminals

  • Test all lights, including headlights, brake lights, turn signals, and clearance lights, to ensure they are functioning correctly

7. Tire Pressure and Condition

Tires are a critical component of your semi-truck, affecting fuel efficiency, handling, and braking. Unfortunately, tire pressure and condition are often overlooked during pre-trip inspections. To ensure your tires are in good shape:

  • Check the tire pressure of each tire, including the spare, and adjust as necessary according to the manufacturers or fleets recommendations

  • Inspect for cuts, bulges, uneven wear, or other damage to the tires

  • Look for signs of excessive or uneven wear, which may indicate a need for an alignment or suspension adjustment

8. Fluid Levels

Your semi-truck relies on various fluids to keep its engine, transmission, and other systems running smoothly. Neglecting to check these fluid levels can lead to expensive and time-consuming repairs. Always:

  • Check the engine oil level and top off if necessary

  • Inspect the coolant level and add as needed

  • Ensure that the brake, power steering, and transmission fluids are within the appropriate ranges

  • Look for any signs of leaks around the engine or transmission

9. Mirrors and Windows

Clear visibility is crucial for safe driving, and mirrors and windows are integral to maintaining that visibility. However, many drivers overlook the importance of checking their mirrors and windows during a pre-trip inspection. To ensure clear visibility:

  • Clean all mirrors and windows, both inside and out

  • Inspect mirrors for cracks, damage, or improper adjustment

  • Check the windshield and side windows for chips, cracks, or other damage that could impair visibility

10. Emergency Equipment

Every semi-truck should be equipped with emergency equipment to handle unexpected situations on the road. Unfortunately, many drivers forget to inspect these items during their pre-trip inspection. To make sure you’re prepared for emergencies:

    • Check that your fire extinguisher is fully charged and not expired

    • Inspect your reflective triangles or flares for damage or wear

    • Ensure that you have a properly stocked first-aid kit on board

    • Make sure you have spare fuses!

A thorough pre-trip inspection is essential for the safety and efficiency of your semi-truck. By taking the time to check all the aforementioned items, you can help prevent unexpected breakdowns, accidents, and costly repairs. Adopting a routine that includes inspecting these commonly missed points will ultimately save you time, money, and stress while out on the road. Happy trucking and stay safe!

Matt Slay

With a passion for writing and a former roadside assistance agent; Matt covers topics from life on the road to mechanical breakdowns. When he's not writing, he enjoys spending time on the water every chance he can find.