CDL Pre-Trip Inspection Practice Test
Fifteen original practice questions on what to check during a pre-trip inspection, what counts as a defect and how the in-cab brake checks work.
Pick an answer for each question. You’ll see right away if it’s correct and why.
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Answer: C. 4/32 inch 49 CFR 393.75 requires at least 4/32 inch in a major tread groove on the front tires, measured away from tie bars or humps.
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Answer: A. 2/32 inch All tires other than the front (steer) tires need at least 2/32 inch in a major groove under 49 CFR 393.75.
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Answer: B. More than 10 degrees, about 2 inches at the rim of a 20-inch wheel Play beyond about 10 degrees, roughly 2 inches at the rim of a 20-inch wheel, can make the truck hard to steer.
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Answer: D. Up to about 3/4 inch The pre-trip test guide says belts should be snug, with up to about 3/4 inch of play at the center, and free of cracks or frays.
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Answer: A. Pump the pedal three times, then hold it down for five seconds; it should not sink Pump the brake pedal three times and hold firm pressure for five seconds. If the pedal moves, there may be a leak to fix before driving.
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Answer: C. 4 psi With the engine off and the foot brake held down, the limit is 3 psi in one minute for a single vehicle and 4 psi for a combination.
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Answer: B. Keep fanning until the parking brake valve (and tractor protection valve on a tractor-trailer) pops out After the warning check, keep fanning the pedal until the valves pop out and the spring brakes set. Then build pressure back up to governor cut-out.
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Answer: D. Pull forward at about 5 mph, apply the brake and check that the truck stops without pulling to one side At about 5 mph, apply the service brake firmly. Pulling to one side or a delayed stop can mean brake trouble.
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Answer: A. With the parking brake set, put it in a low gear and gently pull forward against it Set the parking brake, select a low gear and gently try to pull forward. On a combination, test the tractor and trailer parking brakes separately.
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Answer: C. The lug nuts may be loose Rust streaks or shiny threads are signs a lug nut is working loose. All lug nuts should be present, uncracked and tight.
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Answer: B. The locking jaws fully closed around the kingpin The jaws must be closed around the shank of the kingpin, the trailer should sit flat on the skid plate with no gap, and the release arm should be in the engaged position.
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Answer: D. Spare fuses (if used), three red reflective triangles and a charged, rated fire extinguisher Check for spare electrical fuses (unless the truck uses circuit breakers), three red reflective triangles and a properly charged and rated fire extinguisher.
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Answer: A. It is a defect; rims cannot have welding repairs Check rims for damage or bending. Welding repairs on rims are not allowed, so report it as a defect.
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Answer: C. It should go out after a moment The ABS lamp comes on and then goes off. If it stays on, ABS is not working. On a trailer, a yellow lamp that stays on at the left side means the same.
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Answer: B. Review it and sign to acknowledge the certified repairs 49 CFR 396.13 says the driver must be satisfied the vehicle is safe, review the last report and sign it to acknowledge that required repairs were certified.
About this test
The pre-trip vehicle inspection is the first part of the CDL skills test. Federal rules (49 CFR 383.133) set the order: pre-trip inspection, then basic vehicle control, then the on-road drive, and if you fail one part you cannot go on to the next. You walk around the truck, point to each item and tell the examiner what you are checking and what a defect would look like. In many state manuals, doing the in-cab air brake check wrong is an automatic failure.
These are practice questions, not the official test. They help you learn the limits and defects, but the real exam is a hands-on walkaround. Use your state's CDL manual (the pre-trip inspection section) and practice saying each item out loud on a real truck.
More CDL practice tests
- New York State Commercial Driver's Manual (CDL-10), Sections 11-13: Pre-Trip Vehicle Inspection Test
- New York State Commercial Driver's Manual (CDL-10), Section 2: Driving Safely (vehicle inspection)
- 49 CFR 393.75: Tires (eCFR)
- 49 CFR 396.13: Driver inspection (eCFR)
- 49 CFR 383.133: Test methods (eCFR)
This page is general information, not legal or tax advice. Rules change; confirm with FMCSA, the IRS or your state before you file.
Questions carriers ask
Can I do the pre-trip inspection test in Spanish?
No. Federal rules (49 CFR 383.133) prohibit interpreters during the skills test, and the applicant and examiner may not communicate in any language other than English. Practice the item names and defects in English.
What happens if I fail the pre-trip part?
Under 49 CFR 383.133, you cannot continue to the next segment (basic control or the road test). Passed segments only stay valid during the initial CLP period, so ask your testing site about retest rules.
Do I still inspect the truck after I get my CDL?
Yes. Under 49 CFR 396.13, before driving you must be satisfied the vehicle is safe, review the last driver vehicle inspection report when one is required, and sign it to acknowledge any certified repairs.