What a Real Pre-Trip Trailer Inspection Looks Like

A pre-trip inspection is more than a DOT requirement — it’s your first line of defense against mechanical failure, missed loads, or a roadside violation. At Anderson Trucking Service (ATS), two seasoned trucking professionals teamed up to walk through a full trailer inspection, sharing tips, reminders, and safety insights that every commercial driver can benefit from.

This isn’t theory. It’s the kind of real-world knowledge that comes from years of experience working with drivers, customers, equipment, and safety teams across the country.

Here’s a breakdown of what they covered and what you should look for every time you get behind the wheel.

Start at the Front: Air, Coupling, and Structure

They begin at the front of the trailer, starting with the glad hands and air lines. You’re checking for cracks, worn seals, and anything that might lead to an air leak.

From there, move on to the kingpin and fifth wheel, where a secure, visible lock-in is critical. Remember, it’s not enough to hear the click: you’ve got to get under the trailer and confirm the jaws are wrapped around the kingpin.

Next, check the landing gear, making sure all bolts are tight and nothing is bent or cracked. A quick scan of crossmembers and the primary frame will help you catch any structural issues early. Bolts missing? Rust at key joints? Those are red flags that can get you sidelined.

Securement and D-Rings

While inspecting the trailer structure, make sure D-rings and other securement points are in place and undamaged. Improper or compromised securement can affect how a load shifts — and how the trailer handles under weight.

One important note: check the dunnage. It should be wider than it is tall to keep it from rolling or slipping under pressure. It’s a small detail, but one that can make or break load safety.

Lights, Tape, and Turn Signals

Lighting is one of the most common inspection fails. Every light needs to be operational, turn signals, brake lights, marker lights, and four-ways. And don’t forget the reflective tape down the side of the trailer. Federal regulations require at least 50% coverage, and it should be clean and unbroken.

A clean light is a bright light. Whether you’re hauling in Texas heat, through Minnesota snow, or on a dusty job site out west, road grime can make lights harder to see. Wipe them down regularly to maintain visibility, especially at night.

Tires and Air Pressure

Tire condition and pressure are make-or-break items on a pre-trip. Don’t just thump them with a hammer. Use a gauge and check for consistent pressure between duals. Mismatched tire pressure causes uneven wear, reduces fuel efficiency, and increases your risk of a blowout.

In this inspection, both tires read 113 PSI, right in line. That level of precision may not always be possible, but you should never see a difference of 10, 15, or 20 PSI between tires.

Also inspect the:

• Wheels for cracks or bent edges

• Lug nuts for tightness and signs of movement

• Hub seals for leaks

• Slider locks for full engagement

Brake System and Suspension

From the air canisters to the slack adjusters, everything in the brake system needs to be intact, connected, and secure. Listen closely for leaks. Any hissing or escaping air could indicate a problem with the hoses or fittings.

The professionals in the video highlight the importance of checking:

• Brake shoes for wear (look for manufacturer wear bars or cutout designs)

• Slack adjusters and S-cams for full range of movement

• Cotter pins and retainers for proper installation

• Airbags for dry rot or cracks

• Push rods for correct connection and secure mounting

If any of these components are loose or damaged, braking performance suffers. That’s a risk no one wants to take.

Rear Trailer Components

As you move to the rear of the trailer, don’t forget to check:

• DOT bumper for cracks or missing bolts

• Mud flaps and mounting brackets

• Brake and turn lights

• Slack adjusters on both axles

A final note from the team: be mindful of the hub area. Loose hub bolts or missing lubrication can cause a catastrophic failure, including wheel loss. It’s not common, but when it happens, the results are serious. 

How Far Should Brake Lights Be Visible?

According to one experienced ATS team member, you should aim for brake light visibility at 650 feet. That’s the same distance you need to come to a complete stop at highway speeds. If your lights are dirty, cracked, or dim, you’re not just risking a citation — you’re compromising your safety and that of the motoring public.

The Little Things Make a Big Difference

The professionals performing this inspection emphasize one big takeaway: the small details are what DOT officers and serious carriers notice first. Clean lights, working signals, intact reflectors, and fully inflated tires make your truck inspection-ready at a glance. But they also help protect your load, your license, and your bottom line.

Why It Matters

Whether you’re hauling wind components in the Midwest or steel beams in the South, every pre-trip inspection gives you the chance to take control of your day before the road does. The DOT isn’t the only one watching. Your career, your safety, and your paycheck depend on staying alert, informed, and ahead of the game.

Drive safe. Inspect smart. And keep it tight.