Free Printable Checklist
Download the complete pre-trip inspection sequence. Print it. Take it to the yard. Walk the truck with it.
This Is the Test That Scares People the Most
The CDL skills test has three parts: the pre-trip inspection, basic vehicle control, and the road test. Most people worry about the road test. Most people fail the pre-trip.
It is not because the pre-trip is harder. It is because people underestimate it. They spend all their study time practicing backing and shifting and treat the walk-around like something they can wing on test day. You cannot wing it. The examiner has a checklist. You either call out every item on that checklist or you fail. There is no partial credit.
The good news: the pre-trip is the most predictable part of the entire CDL test. The truck does not change. The components do not move. The checklist is public. If you memorize the sequence and practice it out loud ten times, you will pass. This article gives you the sequence.
What the Examiner Wants to See
The examiner is not trying to trick you. They are checking whether you can systematically inspect a commercial vehicle and identify components that affect safety. They want to hear you name each component, explain what you are checking for, and demonstrate that you know why it matters.
You do not need to be a mechanic. You do not need to know how to fix anything. You need to know what to look at, what it should look like when it is right, and what it looks like when it is wrong.
The test typically takes 30 to 45 minutes. You walk around the truck in a specific sequence, calling out components as you go. Some states let you use a checklist or note card. Some do not. Check with your state’s DMV before test day.
The Sequence: How to Walk the Truck
Every CDL school teaches a slightly different order, but the standard approach is to start at the front of the vehicle and work your way around clockwise. Here is the full sequence broken into sections.
Engine Compartment
The examiner will ask you to raise the hood or tilt the cab. Once the engine is exposed, you need to identify and check:
Fluid levels. Engine oil (check dipstick, look for level between min and max). Coolant level (check overflow reservoir, should be between lines). Power steering fluid (check reservoir). Windshield washer fluid.
Belts and hoses. Look at the serpentine belt and any accessory belts. Check for cracks, fraying, or excessive wear. Check hoses for bulges, cracks, or leaks. Look at connections and clamps for tightness.
Leaks. Look under the engine for any puddles or drips. Oil, coolant, power steering fluid, fuel. No leaks is what you want to say. If you see one, call it out.
Wiring. Look for cracked, frayed, or loose wiring. Nothing should be dangling or rubbing against moving parts.
Steering components. Identify the steering gear box and the power steering pump. Check the steering linkage for looseness or damage. Look at the pitman arm and drag link if visible.
Water pump. Identify it. Check for leaks around the gasket.
Air compressor. Identify it. Check the belt that drives it. Check for leaks at fittings.
Alternator. Identify it. Check that it is mounted securely. Check the belt.
When you close the hood, make sure it latches securely. Say it out loud: “Hood is latched and secure.”
In-Cab Inspection
Get in the cab. The examiner follows you through a checklist of interior items:
Parking brake. Make sure it is set. Say it.
Seat belt. Check that it works, retracts, latches.
Emergency equipment. Fire extinguisher (check that it is charged, pin is in place, accessible). Reflective triangles (three required). Spare fuses if the vehicle uses fuses.
Mirrors. Adjust all mirrors. Left flat, left convex, right flat, right convex. You should be able to see down both sides of the trailer and the lane next to you.
Gauges. With the engine running, check: oil pressure (should come up within seconds of starting), temperature gauge (should be in normal range), voltmeter or ammeter (should show charging), air pressure gauge (should build to operating range, typically 100-125 PSI).
Steering wheel. With the engine running, check for free play. Turn the wheel until the tires just begin to move. Free play should not exceed about two inches on a manual steering system, roughly 10 degrees of rotation. Say what you are checking and why.
Windshield and wipers. Check the windshield for cracks, chips, or anything that obstructs the view. Check that wipers work and the blades are in good condition.
Heater and defroster. Check that they function.
Horn. Test it. It needs to work.
Lights. Turn on headlights, check high and low beam. Turn on four-way flashers. You will verify these work from outside during the walk-around.
Air Brake Check
This is its own section and it is where a lot of people lose points. There are specific tests you must perform in a specific order:
Air pressure build-up. With the engine running, air pressure should build from 85 to 100 PSI within 45 seconds. Watch the gauge. Call out what you are checking.
Governor cut-out. The air compressor should cut out between 120 and 145 PSI (varies by vehicle). The gauge will stop climbing. Note the pressure.
Air leakage rate. Turn off the engine. With brakes released, the air pressure should not drop more than 2 PSI in one minute for a single vehicle, or 3 PSI for a combination vehicle. With brakes applied (press the brake pedal), the drop should not exceed 3 PSI in one minute for single, 4 PSI for combination.
Low air pressure warning. Fan the brake pedal to reduce air pressure. The low air warning light or buzzer should activate before pressure drops below 60 PSI. Call it out when it activates and note the pressure.
Spring brakes (parking brake pop-out). Continue fanning the brakes. The parking brake valve (tractor protection valve on combinations) should pop out between 20 and 45 PSI. This means the spring brakes have engaged automatically. This is a critical safety feature. Call it out.
Brake pedal check. With the engine running and air pressure built to operating range, press the brake pedal firmly and hold it for five seconds. It should not drift to the floor. If it drifts, there is a leak in the hydraulic or air system.
Practice this sequence until you can do it from memory. The air brake check is the single most common section where people fail because they forget a step or do them out of order.
Front of Vehicle (Outside)
Walk to the front. Check:
Headlights. Both working (you turned them on inside). Check for cracks in the lenses.
Turn signals. Both front turn signals working. Check lenses.
Windshield. Check again from outside for cracks, illegal stickers, or obstructions.
Front bumper. Secure, not dented or damaged in a way that is hazardous.
Front axle. Look at the front axle beam for cracks or damage.
Steering linkage. Look at the tie rods, drag link, and steering arm. Check for looseness, missing cotter pins, or damage.
Suspension. Check the leaf springs (or air bags if equipped). Look for cracked, broken, or missing leaves. Check the spring mounts, hangers, and U-bolts. Check shock absorbers for leaks or damage.
Brakes. Look at the brake drums or rotors. Check for cracks. Check brake pads or shoes for thickness. Look at the brake hoses and lines for leaks, cracks, or damage. Check the slack adjuster. Pull it by hand. It should not move more than about one inch.
Tires. Check both front tires. Look for tread depth (minimum 4/32 on steer tires). Check for cuts, bulges, or exposed cords. Check sidewalls. Check tire pressure visually (no flat spots). Check the valve stem and cap. Check lug nuts for tightness or rust streaks that indicate looseness.
Wheel and rim. Check for cracks, dents, or damage. Check that lug nuts are present and tight.
Driver Side
Walk down the driver side of the vehicle. Check:
Fuel tank. Secure. No leaks. Cap is on and tight.
DEF tank (if equipped). Same checks.
Steps and handrails. Secure, not bent or broken.
Air lines and electrical connections (between tractor and trailer on combinations). Check that glad hands are secure, no air leaks, lines are not dragging. Check the electrical cord connection.
Frame. Look at the frame rails for cracks or damage.
Drive shaft. Check that it is secure, no missing U-joints.
Exhaust system. Check for leaks, loose connections, damage. The exhaust should not be leaking near fuel lines or air lines.
Rear axle(s). Same checks as the front: springs, mounts, U-bolts, shocks, brakes, drums, slack adjusters, tires, wheels, lug nuts.
Rear of Vehicle
Tail lights, brake lights, turn signals. Have someone press the brakes or use the four-way flashers to verify. Check lenses for cracks.
Reflectors. Red reflectors on the rear.
Mudflaps. Present, not torn, hanging at the correct height.
License plate and light. Plate present. Light works.
Doors (if trailer). Secure, hinges in good condition, latches work.
Landing gear (on trailers). Raised fully, handle secured, no damage to supports.
Kingpin area (if walking under). Fifth wheel locked, no visible gap, release arm in locked position.
Passenger Side
Mirror the driver side. Walk back toward the front checking all the same components on the passenger side: fuel tank, frame, suspension, brakes, tires, wheels, air lines.
The Mistakes That Fail People
Forgetting the air brake check. It is a separate scored section. If you skip it or do it out of order, you fail.
Not saying it out loud. The examiner cannot read your mind. If you look at the tire but do not say “checking tread depth, looking for cuts, bulges, or exposed cords, minimum 4/32 on steer tires,” you do not get credit for checking the tire. Narrate everything.
Rushing. The pre-trip is not timed in a way that rewards speed. A thorough, methodical inspection at a steady pace is exactly what the examiner wants to see. Going fast looks like you are skipping things. Slow and steady passes the test.
Skipping components you cannot see. If a brake drum is hard to see, get down and look. If a spring hanger is behind a wheel, say you are checking it and describe what you are looking for even if visibility is limited. The examiner knows the truck. They know what is hard to see. They want to know that you know it is there.
Not checking both sides. Everything on the left exists on the right. If you check the left front tire and forget the right front tire, you lose points. The walk-around is designed so you hit everything on both sides.
How to Study
Walk the truck ten times before test day. Not five. Ten. Out loud. Every component. Every time. By the seventh walk-through, you will be able to do it in your sleep. By the tenth, you will be bored. Bored is ready.
Use a checklist until you do not need one. Write the sequence on an index card. Walk the truck with the card. Put the card away. Walk the truck again. Check what you missed. Repeat until the card stays in your pocket.
Practice the air brake check separately. Sit in the truck and do the air brake sequence five times in a row. Build up, governor cut-out, leakage rate, low air warning, spring brakes, brake pedal. Say the PSI numbers out loud. Know the acceptable ranges cold.
Study with a partner. Have someone follow you with a checklist and check off what you call out. The items you consistently miss are the items you need to drill.
Test Day
Show up early. Dress like someone who takes the job seriously. Be polite to the examiner. They are not your enemy. They pass most people who are prepared and fail most people who are not. Be prepared.
Start at the engine compartment. Work clockwise. Narrate everything. Do not rush. Do the air brake check when prompted. Finish by verifying all lights with a helper.
When you are done, you will know whether you passed. Not because the examiner tells you, but because you will know whether you called out every item or not. The test is binary. You either know the truck or you do not. Ten walk-throughs and you know the truck.
Go pass it.
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Sponsored by Shiftlane Academy
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