Study Guide

CDL Pre-Trip Inspection Checklist

The pre-trip inspection is one of the most-failed parts of the CDL exam. This complete checklist walks you through every component an examiner expects you to identify — in the right order.

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Engine Compartment

  • Oil level and leaks
  • Coolant level and hoses
  • Power steering fluid
  • Belts (alternator, water pump)
  • Battery and connections
  • Wiring (no cracks or frays)

Front of Vehicle

  • Lights and reflectors clean and working
  • Windshield free of cracks
  • Wipers and washer fluid
  • Mirrors adjusted and secure
  • Tires: tread depth, inflation, no damage

Side & Suspension

  • Door hinges and seal
  • Fuel tank secure, cap tight
  • Drive shaft straight and clean
  • Springs, shocks, and U-bolts intact
  • Frame and crossmembers

Rear & Trailer

  • Lights and reflectors
  • Mud flaps secure
  • Trailer coupling and fifth wheel
  • Brake lines properly connected
  • Cargo secured, doors latched

In-Cab Inspection

  • Air gauge builds 85–100 psi in 45 sec
  • Low-air warning at 60 psi
  • Service brake check
  • Parking brake holds
  • Steering play under 10°
  • Horn, defroster, heater, and gauges

Why the Pre-Trip Inspection Matters

Examiners use the pre-trip inspection to test more than memory — they want to see that you understand vehicle safety. Verbalize each check, point to the component, and explain what you're looking for. A confident, structured walkaround is the single biggest factor that separates passing scores from failures.

Frequently Asked Questions

Get the Complete Pre-Trip Checklist

Read the full step-by-step pre-trip inspection guide with examiner tips and memorization techniques.

Read the Full Guide