DOT Pre-Trip Inspection Checklist for Truckers

By Josh Weldon, Owner & Lead Diesel Technician, Weldon's Truck & Trailer — ASE-certified

Download the printable PDF version of this checklist

A proper pre-trip inspection is your first line of defense against breakdowns, DOT violations, and out-of-service orders. It is also a federal requirement under FMCSA rules, and it is part of the CDL skills test for a reason.

Use this checklist before every trip. It is organized the way an inspector — and a smart driver — works through a rig: engine compartment first, then a walk-around, the coupling system, and finally the in-cab checks. Print it, keep a copy in the cab, and work top to bottom every time.

Engine Compartment (Engine Off)

Engine oil level and condition
Coolant level and hoses (no leaks, soft spots, or chafing)
Power steering fluid level and lines
Belts — no fraying, proper tension
Water pump and alternator mountings secure
Leaks under the engine (oil, coolant, fuel)
Air compressor and lines secure
Wiring — no cracked, frayed, or loose connections

Exterior Walk-Around

Tires — tread depth, even wear, proper inflation, no cuts or bulges
Steer tires at least 4/32" tread; others at least 2/32"
Wheels and rims — no cracks, all lug nuts present and tight
No oil or grease leaks at hubs (check seals)
Brake drums/rotors and visible brake components
Suspension — springs, hangers, U-bolts, shocks, airbags
Frame and crossmembers — no cracks or bends
Lights and reflectors — all clean, working, correct color
Mirrors clean and properly adjusted
Fuel tanks secure, caps tight, no leaks
Exhaust system secure, no leaks
Mud flaps present and secure

Coupling System (Tractor-Trailer)

Fifth wheel secure, no cracks or excessive play
Kingpin and apron in good condition
Locking jaws fully closed around the kingpin
Release arm properly seated and safety latch engaged
No gap between trailer apron and fifth wheel
Air lines and electrical line secure, no leaks, no chafing
Landing gear fully raised, crank handle secured

In-Cab & Brake Checks

Gauges and warning lights function on startup
Wipers, washers, heater, and defroster work
Horn (city and air) works
Seat belt secure and not frayed
Steering play within limits
Air pressure builds to governor cutout (around 120 psi)
Low-air warning activates before pressure drops below 60 psi
Air pressure leak-down test within limits (engine off, brakes applied)
Parking brake holds against a gentle pull
Service brake stops the vehicle and does not pull to one side
Required paperwork, registration, and emergency equipment on board

Find a defect you cannot safely fix yourself? Do not roll. Call Weldon's Truck & Trailer at (334) 759-7020 — we will come to you anywhere within our 200-mile service area.

Frequently Asked Questions

How long should a DOT pre-trip inspection take?

A thorough pre-trip inspection typically takes 15 to 30 minutes. Rushing it is the most common reason drivers miss a defect that later becomes a roadside breakdown or an out-of-service violation.

What is the minimum legal tread depth for commercial tires?

Federal rules require at least 4/32 inch of tread on steer tires and at least 2/32 inch on all other tires. Replace tires before they reach these limits to stay safe and compliant.

What happens if I find a defect during my pre-trip?

If the defect affects safe operation, the vehicle should not be driven until it is repaired. Document it, and call a mobile repair service like Weldon's if you cannot fix it yourself.

Is a pre-trip inspection legally required?

Yes. FMCSA regulations require drivers to be satisfied the vehicle is in safe operating condition before driving, and to review the last driver vehicle inspection report. A documented pre-trip protects you in an audit or after an incident.

About the Author

Josh Weldon — Owner & Lead Diesel Technician, Weldon's Truck & Trailer. Josh Weldon is the owner and lead technician at Weldon's Truck & Trailer in Kingman, Arizona. An ASE-certified diesel technician with more than 10 years of hands-on experience, Josh has personally handled thousands of roadside repairs along the I-40 and US-93 corridors. He founded Weldon's to give drivers fast, honest, expert help when they break down far from home.

ASE-Certified Diesel Technician
10+ years in commercial truck & trailer repair
5,000+ trucks serviced across AZ, NV & CA
Hands-on specialist on the I-40 / US-93 corridors

Need truck or trailer repair? Call (334) 759-7020 for 24/7 mobile service.