The DOT Annual Inspection Checklist for Owner Operators

Every commercial vehicle needs an annual inspection, trailers included. For an owner operator it is a fixed cost and a fixed date, and the only real variable is whether the truck passes first time or comes back with a list.

The inspection covers defined areas, and none of them are secret. Walking the truck yourself a week beforehand turns a potential failure into a scheduled repair, which is a much better outcome than discovering it on inspection day with a load booked.

Brakes, which is where most failures happen

Brake defects lead every violation table, so this is where to spend your attention.

• Pushrod stroke at every wheel end, measured against the limit for your chamber type and size. This is the single most common finding.
• Lining thickness at each wheel end, and drum or rotor condition including cracks and wear beyond the discard dimension.
• Air system: build up time, governor cut in and cut out, leak down rate with the engine off, and the low pressure warning working.
• Air dryer functioning and purging, with no water coming out of the tanks when you drain them.
• Chambers, slack adjusters, S-cams and spider hardware secure and free of damage.
• ABS lamp cycles at start up and goes out. If it stays on, that alone is a violation on tractor or trailer.
• Parking brake holds and releases cleanly.

Tires and wheels

Tread depth is measured in the major grooves, with a higher minimum required on steer tires than on other positions. Beyond depth, the inspector is looking for sidewall damage, exposed cords, bulges, cuts, and any sign of a tire that has been run flat.

On the wheels themselves: cracks, particularly around the stud holes, elongated stud holes, missing or loose fasteners, and welded repairs on a wheel, which are not permitted. Check the duals are not touching and that the valve stems and extensions are intact.

Steering and suspension

Play at the steering wheel beyond the allowed amount, worn kingpins, tie rod ends and drag link, and a steering gear that is loose on its mounting are all findings. On the suspension the inspector is looking for cracked or broken spring leaves, broken or missing spring hangers and u-bolts, torn air bags, and loose or missing torque rods.

Shock absorbers get looked at for leaks and for being physically attached, which sounds obvious until you have seen how many are hanging by one end.

Frame, coupling and exhaust

Cracks in the frame rails and crossmembers, particularly around suspension mounting points, and any previous repair that does not look like it followed a proper procedure. Loose or missing frame fasteners.

On the fifth wheel: mounting secure with no cracks, correct locking operation, no excessive play between the upper and lower coupler, and the kingpin and pickup plate in good condition. On the trailer, landing gear operating properly and not bent.

The exhaust must not leak beneath the cab or sleeper, and must be securely mounted with nothing rubbing on fuel lines or wiring.

Lighting and reflectors

Every required lamp working: headlights on both beams, stop, tail, turn, hazard, marker and clearance lamps, licence plate lamp. Reflective tape present and not damaged or missing sections. Trailer lighting is where most of these turn up, and corrosion is nearly always the cause.

Cab, glass and safety equipment

Windshield cracks in the driver critical area, wipers and washers working, mirrors present and undamaged, the horn working, seat belts functional and not frayed, and the defroster working.

Required equipment on board: fire extinguisher charged and secured, three warning triangles, and spare fuses where applicable. These are easy items to fail on and slightly embarrassing ones.

Book the repairs and the inspection together

If your walkaround finds items, get them booked into the same visit as the inspection. The alternative is failing, arranging repairs, and coming back, which costs you a second trip and potentially a second inspection fee.

Book the slot ahead of time as well. Inspection appointments fill up, particularly toward the end of a month, and a decal running out while you are waiting for a booking is an avoidable problem.