Complete Pre-Trip & Post-Trip Inspection Guide for Truck Drivers

Being thorough isn’t optional — it’s your legal responsibility and your first line of defense against mechanical failure and DOT violations. Whether you’re starting or ending your shift, this walk-around guide covers what most miss — and what will get you pulled over or sidelined.

🔧 ENGINE COMPARTMENT (Under the Hood)

What to Check:

• Oil level – use dipstick; refill if low

• Coolant level – check surge tank, look for leaks or crusting

• Power steering fluid – check dipstick if accessible

• Belts – no cracks, frays, or excessive slack

• Hoses – no bulges, leaks, or signs of wear

• Leaks – look under truck and around engine bay

TIP: Leaks = inspection failure. Wipe clean in post-trip so you can detect new leaks in the next pre-trip.

🛞 STEERING & SUSPENSION

• Steering gear box – secure, no leaks

• Pitman arm / drag link / tie rod ends – no excessive play

• Leaf springs – not cracked or shifted

• U-bolts – tight and unbroken

• Shock absorbers – no leaks, firmly mounted

🧱 BRAKES (Tractor & Trailer)

• Air lines – not tangled, chafed, or leaking

• Brake chambers – no cracks, securely mounted

• Slack adjusters – no more than 1-inch of play

• Brake pads – must have legal thickness (≥¼ inch)

• Drums/rotors – no cracks, grooves, or oil contamination

• Trailer brake application – pull gently and confirm response

Pro Tip: If you hear hissing while parked, you have an air leak — find it before DOT does.

🛞 WHEELS, RIMS & HUBS

• Rims – no cracks or illegal welds

• Lug nuts – all tight, no rust trails or shiny threads

• Hub oil seals – no visible oil leaks

• Tires:

  • Minimum tread: 4/32” steer, 2/32” drive/trailer

  • Even wear, proper inflation

  • No sidewall bubbles, cuts, or cords exposed

🔄 COUPLING SYSTEM (Fifth Wheel & Kingpin)

• Fifth wheel plate – greased, no cracks

• Locking jaws – visibly closed around kingpin

• Kingpin – not bent or worn

• Air lines & electrical (glad hands & pigtail) – connected, no damage

• Sliding fifth wheel – locked and pins secure (if applicable)

• Release arm – in locked position

NOTE: If you’ve disconnected the trailer, always check coupling components before reconnecting.

🛻 TRAILER WALKAROUND

• Landing gear – cranked all the way up, secure

• Crossmembers & floor – no broken welds or sagging

• DOT reflective tape – intact all the way around

• Side panels & doors – secure and undamaged

• Door seals – no gaps if hauling reefer

🔦 LIGHTS & ELECTRICAL

Check with headlights ON and flashers activated:

• All clearance lights

• Headlights (high/low)

• Brake lights

• Turn signals (tractor & trailer)

• 4-ways (tractor & trailer)

• Reverse lights

Don’t miss: Tag light and ABS light on trailer (required and often missed)

📋 IN-CAB INSPECTION

• Horn (city and air)

• Wipers & fluid

• Defrost & HVAC controls

• Mirrors – clean, adjusted properly

• Gauges – oil pressure, air pressure, coolant temp, volts

• Fire extinguisher – charged and mounted

• Triangles / reflective devices – 3 minimum

• Seatbelt – operational and not frayed

🕵️‍♂️ POST-TRIP: WHAT TO DO DIFFERENTLY

While pre-trip is to prevent problems, post-trip is about identifying issues for repair before the next shift:

1. Document any defects on your DVIR

2. Check for leaks or drips that weren’t there before

3. Note tire damage from the day

4. Make sure all lights still function

5. Look for wear on glad hands and hoses from coupling/uncoupling

6. Verify all paperwork, tags, and seals are intact

🔚 Final Word

DOT inspectors are trained to spot what drivers miss. The cost of a blown tire, brake issue, or tow is way higher than 15 minutes of attention. You are responsible. Skipping steps is gambling with your CDL, your paycheck, and your life.