Inspection & Pre-Trip
Cover the inspection flow and what to catch before rolling.
CDL success depends on being systematic before the truck moves. This lesson is about inspection order, what each check is proving, and how pre-trip details connect to roadside safety and test scoring, so you can explain not only what to inspect but why a missed defect matters once the vehicle is in service.
The rules that matter
- A pre-trip inspection is required before every trip, and a critical defect keeps the truck parked until it's fixed — schedule pressure is not an exception.
- Test the service brakes by rolling forward at about 5 mph and braking firmly; the truck must stop straight, with no pull to either side.
- Federal law requires a fire extinguisher, spare electrical fuses, and three warning triangles on board — missing any one is an out-of-service violation.
- Secure every load with blocking, bracing, and tie-downs, then re-check it within the first 50 miles and again every 150 miles or 3 hours.
- Steering-axle tires need at least 4/32 inch of tread; all other tires need at least 2/32 — and no tire may show fabric or have an audible air leak.
- Inspection is three moments, not one: a full pre-trip, checks en route, and a post-trip review at the end of the day.
- A vehicle marked out of service stays put: nobody may operate or tow it, or remove the sticker, until every required repair is done.
- Deliver a roadside inspection report to your carrier at the next terminal, or transmit it immediately if you will not reach one within 24 hours.
- You only owe a driver vehicle inspection report when a defect was found or reported — but you always owe a review and signature on the last one before driving.
- Every commercial vehicle, and every unit of a combination, must have passed a periodic inspection within the last 12 months with the proof carried aboard.
- Name the defect, do not just report a feeling: steering play, a cracked spring hanger, a gap at the fifth wheel and a worn universal joint are each a specific failure.
The lessons in this module
Each lesson is one short set of questions. If you've missed questions in this module before, a few come back at the start. Progress saves automatically; sign in only if you want cross-device sync.
Lesson videos
4 lessons · See all →Read this in the handbook
Look for these sections: Vehicle Inspection, Pre-Trip Inspection, Roadside Inspections, Vehicle Maintenance and Repair, Vehicle Systems and Malfunctions.
This content comes from the federal FMCSA regulations (49 CFR), not a state handbook, so the rules are the same nationwide. Your state agency may add its own endorsement requirements on top.
Where these rules come from
We do not copy official handbooks — most states do not allow it. What we do instead: state the rule in our own words, then name the official document behind it. 95 questions in this module cite 27 official documents, none checked earlier than 2026-05-17. The 6 most-cited are below.
| Official document | Sections cited |
|---|---|
FMCSA Commercial Driver License Manual ↗ National · Checked 2026-05-17 | Section 11: Vehicle Inspection Test, Sections 2 and 11: Vehicle Inspection and Basic Vehicle Control Skills |
FMCSA Commercial Driver's License Manual ↗ National · Checked 2026-06-14 | Section 11.1 - Why Inspect, Section 11.4 - Belts And Hoses, Section 11.4 - Engine Compartment Checks |
49 CFR § 396.9 ↗ National · Checked 2026-08-13 | Certification of corrected violations, Inspection of motor vehicles in operation, Motor carrier disposition of inspection reports |
FMCSA CDL Manual ↗ National · Checked 2026-06-07 | Vehicle Inspection |
FMCSA CDL Testing System — Pre-Trip ↗ National · Checked 2026-06-30 | Pre-Trip Inspection — Air Brake Leakage, Pre-Trip Inspection — Brake Chambers, Pre-Trip Inspection — Coupling Check |
49 CFR § 396.11 ↗ National · Checked 2026-08-13 | Driver vehicle inspection report, Driver vehicle inspection reports, Required report content |
Opening a source takes you to the agency's own site, never to a copy of ours. If a source is out of date or broken, say so from any question.
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Review these questions
You find a critical vehicle safety defect during a pre-trip. What should you do?
- A. Drive carefully to a repair shop
- B. Do not drive until it is repaired
- C. Report it but continue driving
- D. Complete your route first
Show answer
B. Do not drive until it is repaired — Never drive a commercial vehicle with a safety defect that would affect safe operation. Get it repaired first.
Universal rule · checked against FMCSA Commercial Driver License Manual — Section 11: Vehicle Inspection Test · verified 2026-05-17
When checking the coupling system during inspection, you should verify that:
- A. The fifth wheel locking jaws are closed around the kingpin
- B. The paint is not chipped
- C. The trailer is loaded evenly
- D. The fuel tank is full before coupling begins
Show answer
A. The fifth wheel locking jaws are closed around the kingpin — Verify the fifth wheel jaws are securely closed around the trailer kingpin and there is no space between the upper and lower fifth wheel.
Universal rule · checked against FMCSA Commercial Driver License Manual — Sections 2 and 11: Vehicle Inspection and Basic Vehicle Control Skills · verified 2026-05-17
How often must pushout windows and emergency doors on a bus be inspected?
- A. At least every 30 days
- B. At least every 90 days
- C. At least every two years
- D. Only after a reported fault
Show answer
B. At least every 90 days — Buses carry an extra maintenance duty: pushout windows, emergency doors and their marking lights are inspected at least every 90 days and the tests recorded.
Universal rule · checked against 49 CFR § 396.3 — Inspection, repair, and maintenance · verified 2026-08-13
What is the 'brake lining thickness' minimum to avoid an out-of-service condition on a drum brake?
- A. There is no federal minimum — only state requirements
- B. 1/4 inch
- C. 1/8 inch non-steer; 1/4 inch steer axles
- D. 2 mm on all axles
Show answer
C. 1/8 inch non-steer; 1/4 inch steer axles — FMCSA OOS criteria require a minimum brake lining thickness of 1/4 inch on steering axle brakes and 1/8 inch on other axle brakes (measured from the table of the shoe to the lining surface, not at the chamfer).
Universal rule · checked against CVSA North American Standard Out-of-Service Criteria — Vehicle Inspection — Brake Lining Thickness · verified 2026-06-30
During a pre-trip inspection, engine oil level should be checked:
- A. Before every trip
- B. Only if the low oil warning comes on
- C. Once a week
- D. Only in hot weather
Show answer
A. Before every trip — Check engine oil level (along with coolant, power steering, washer fluid) during every pre-trip inspection.
Universal rule · checked against FMCSA Commercial Driver License Manual — Section 11: Vehicle Inspection Test · verified 2026-05-17