Diesel Pickup Pre-Trip Inspection Checklist

You don’t need a CDL to benefit from a pre-trip inspection. A five-minute walk-around before a long drive — and especially before towing — catches the small problems that otherwise become roadside ones. Here’s a practical checklist for diesel pickup owners.

Under the hood (engine cold or warm)

• Engine oil — level on the dipstick, topped with the right oil. A rising level can mean fuel dilution; a dropping level needs investigating.
• Coolant — level at the reservoir; never open a hot cap.
• DEF — top it off before a long trip so you’re not hunting for DEF on the road (and never risking a derate).
• Belt and hoses — a quick look for cracks, fraying, or weeping.
• Washer fluid and a glance for any fresh leaks or puddles under the truck.

Tires and wheels

• Pressure — check cold, including the spare. This matters even more loaded or towing; underinflation builds heat and causes blowouts.
• Tread and condition — look for uneven wear, cuts, bulges, and embedded objects.
• Lug nuts — any signs of looseness (rust streaks, missing nuts).

Lights and signals

Walk around with the four-ways on, then check brake lights, turn signals, headlights, and reverse lights. If towing, check the trailer lights and brakes and the connector.

Towing-specific checks

• Hitch and coupler — properly latched and pinned, safety chains crossed, breakaway cable connected.
• Trailer tire pressure and bearings — trailer tires and bearings fail more than truck ones.
• Brake controller — set and working.
• Load secured and within the truck’s tow/payload ratings.

After you start it

• Watch the gauges: oil pressure, coolant temp, no warning lights (let the glow/wait-to-start cycle finish on a cold start).
• Listen for new noises.
• Test the brakes (and exhaust brake, if equipped) before you get going.

The point

None of this takes long, and it turns “broke down on I-95 with a trailer” into “noticed the low tire in the driveway.” Towing magnifies every weakness, so the pre-trip matters most when you’re loaded.

If your pre-trip turns up something — a leak, a soft brake, a tire wearing wrong, a warning light — our shop can check it out before your trip instead of after it strands you.