Every trucker dreads it—the flashing lights, the weigh station pull-in, or the unexpected roadside inspection. When it’s DOT inspection time, failing just one can mean fines, delays, and a serious hit to your CSA score. But here's the kicker: most inspection failures are completely avoidable with a little know-how and routine attention.

Today, we’ll go through 7 of the most common DOT violations and give you solid tips to steer clear of them.

1. Brake System Violations

Brake-related issues consistently top the list of DOT inspection failures. That’s because there’s zero room for error when you’re hauling 80,000 lbs.

Common violations:

• Brake out-of-adjustment
• Worn or contaminated brake linings
• Leaking or damaged air lines
• Faulty slack adjusters

How to avoid it:

• Manually check pushrod travel on drum brakes.
• Inspect air lines for leaks or chafing.
• Test your air pressure build-up rate.
• Make sure automatic slack adjusters are functioning properly.

Routine pre-trip inspections of the service chamber, S-cam, and air tanks go a long way.

2. Lighting and Reflective Equipment

You’d be surprised how many trucks fail DOT inspections over something as simple as a burned-out marker light. It’s low-hanging fruit for inspectors—and an easy fix.

Typical violations:

• Non-functioning brake or turn signals
• Missing or damaged reflectors
• Inoperable trailer clearance lights

How to avoid it:

• Do a full walk-around light test before hitting the road.
• Replace bulbs immediately—don’t risk it.
• Keep extra fuses and bulbs in your cab.
• Clean lights and reflectors to keep them visible.

3. Tire and Wheel Defects

DOT inspectors have a sharp eye for tires. Uneven wear, low tread depth, or visible damage are all red flags.

Common issues:

• Tread depth below 4/32" (steering) or 2/32" (other tires)
• Exposed cords or sidewall cuts
• Improper inflation
• Mismatched tire sizes

How to avoid it:

• Use a tread depth gauge during your pre-trip.
• Check tire pressure cold, not after driving.
• Look for cupping, cracking, or bulges.
• Don’t ignore slow leaks—get them checked right away.

In Iowa’s changing seasons, tires wear unevenly fast—especially during freeze-thaw cycles.

4. Suspension System Failures

The suspension isn’t just about comfort—it affects load handling, ride height, and braking stability. A bad suspension can lead to a failed inspection and unsafe driving conditions.

Violations include:

• Cracked or missing leaf springs
• Leaking or deflated airbags
• Broken or worn shock absorbers
• Loose or missing U-bolts
  
  

How to avoid it:

• Visually inspect leaf packs and U-bolts during pre-trips.
• Check airbag inflation levels—especially in cold Iowa mornings.
• Listen for clunking or squeaking when maneuvering at low speeds.

5. Improper Load Securement

DOT officers won’t just look under the hood—they’ll check the back, too. Unsecured or poorly secured loads can get you parked immediately.

Violations may include:

• Using the wrong type or number of tie-downs
• Damaged straps or chains
• Unsecured dunnage or equipment
• Shifting cargo

How to avoid it:

• Follow FMCSA tie-down rules: at least 2 tie-downs for items over 10 feet.
• Inspect all load securement gear before each haul.
• Use edge protectors to prevent strap wear.
• Re-check tie-downs after 50 miles and then every 150 miles or 3 hours.

6. Faulty Steering Components

Steering issues are a serious red flag for inspectors because they directly affect control and safety.

Typical violations:

• Excessive play in the steering wheel
• Cracked or missing pitman arm or drag link
• Loose U-joints in the steering shaft
• Leaking power steering fluid

How to avoid it:

• Check for free play (shouldn’t exceed 10 degrees or 2 inches on a 20” wheel).
• Look for fluid leaks around the pump and reservoir.
• Grease steering linkage during routine PM.
• Don’t ignore vibrations or “wandering” on the highway.

7. Logbook and HOS Violations

Even if your rig is mechanically sound, you can still get dinged for paperwork problems—especially Hours of Service (HOS) violations and incomplete ELD logs.

Common mistakes:

• Exceeding drive time limits
• Failing to update duty status
• Logging incorrect locations
• Falsified logs

How to avoid it:

• Use ELD systems correctly—don’t guess.
• Train drivers on proper logkeeping.
• Always have a backup plan for ELD malfunctions (manual logs).
• Double-check entries before inspections.

It’s one of the fastest ways to get put out of service—and it's 100% avoidable.

Final Thoughts: Stay Road-Ready, Not Road-Stopped

DOT inspections don’t have to be a nightmare. Most of the violations are basic, preventable, and easy to spot—if you're paying attention.

At Outer Limits Truck Repair in Oskaloosa, IA, we’ve seen it all—from bad bushings to mismatched tires. Staying ahead of DOT failures means:

• Daily pre-trip inspections
• Sticking to a preventive maintenance schedule
• Training drivers on red-flag symptoms
• Partnering with a trusted local shop that knows the ropes

Because the only thing better than passing a DOT inspection is not sweating it in the first place.

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