How to Perform the 7-Step Vehicle Inspection - Step-by-Step Tutorial

The CDL vehicle inspection test requires you to demonstrate that you know whether your vehicle is safe to drive. This step-by-step tutorial walks you through the 7-step inspection method exactly as you'll perform it during the CDL skills test. You must point to or touch each item, name it, and explain what you're checking and why.

Difficulty Level: Beginner to Intermediate
Time Required: 30-45 minutes for thorough inspection
Prerequisites: Access to a commercial vehicle for practice

Step 1: Vehicle Overview

Begin by approaching the vehicle and reviewing the last inspection report.

Approaching the Vehicle

1. Look at the vehicle's general condition from a distance

2. Check if the vehicle is leaning to one side (indicates suspension/tire problems)

3. Look under the vehicle for fresh leaks:

   • Oil (dark)
   • Coolant (green, orange, or pink)
   • Fuel (clear, strong odor)
   • Power steering fluid

4. Check the area around the vehicle for hazards:

   • People who might walk into your path
   • Other vehicles
   • Low-hanging wires, tree limbs
   • Objects on the ground

Review Inspection Report

• Check for problems noted by previous driver
• Verify repairs were certified complete or unnecessary
• Sign report only if defects were noted and certified

Tip: Always approach from the same direction and follow the same pattern. Consistency helps you remember every step.

Step 2: Check Engine Compartment

First: Set parking brakes and/or chock wheels.

Open Engine Compartment

• Raise hood, tilt cab, or open engine compartment door
• Secure loose items so they don't fall

Fluid Checks

Belt Checks

• Check alternator, water pump, and air compressor belts
• Look for tightness (proper "give") and excessive wear
• Learn the correct tension for your vehicle's belts

Look for Leaks

• Check for fuel, coolant, oil, power steering, hydraulic, and battery fluid leaks
• Inspect wiring for cracked or worn insulation

Close and Secure

• Lower and secure hood, cab, or engine compartment door

Step 3: Start Engine and Inspect Inside Cab

Start the Engine

1. Fasten safety belt
2. Make sure parking brake is set
3. Put gearshift in neutral (or park if automatic)
4. Start engine
5. Listen for unusual noises

Check Gauges Immediately

Important: ABS light should come on then turn off. If it stays on, ABS is malfunctioning.

Check All Controls

Test each control for looseness, sticking, damage, or improper setting:

• Steering wheel
• Clutch pedal
• Accelerator pedal
• Brake pedal (foot brake)
• Trailer brake (if equipped)
• Parking brake
• Retarder controls (if equipped)
• Transmission controls
• Horn(s)
• Windshield wiper/washer
• Light switches (headlights, dimmer, turn signals, flashers, clearance lights)

Check Mirrors and Windshield

• Inspect for cracks, dirt, illegal stickers, obstructions
• Clean and adjust as necessary

Check Emergency Equipment

Verify presence of:

• Spare electrical fuses (unless circuit breakers)
• Three red reflective triangles (or 6 fuses/3 liquid flares)
• Properly charged fire extinguisher

Check Safety Belt

• Securely mounted
• Adjusts and latches properly
• Not ripped or frayed

Step 4: Turn Off Engine and Check Lights

Set Up for Light Check

1. Set parking brake
2. Turn off engine
3. Take key with you
4. Turn on headlights (low beams)
5. Turn on four-way emergency flashers

Check Front Lights

1. Go to front of vehicle
2. Verify low beams are on
3. Verify both four-way flashers are working
4. Push dimmer switch—verify high beams work

Set Up for Walk-Around

1. Turn off headlights and four-way flashers
2. Turn on parking, clearance, side-marker, and identification lights
3. Turn on right turn signal
4. Begin walk-around inspection

Step 5: Walk-Around Inspection

Follow this path around the vehicle, checking each item.

Left Front Side

Driver's Door Area:

• Door glass clean
• Door latches/locks work properly

Left Front Wheel:

• Wheel and rim condition (no missing, bent, broken studs, clamps, lugs)
• Tire properly inflated
• Valve stem and cap OK
• No serious cuts, bulges, or tread wear
• Tread depth at least 4/32" (front tire)
• Check lug nuts (rust streaks indicate looseness)

Left Front Suspension:

• Spring, spring hangers, shackles, u-bolts condition
• Shock absorber condition
• No leaks

Left Front Brake:

• Brake drum or disc condition
• Brake hose condition

Front of Vehicle

Front Axle:

• Axle condition—no damage

Steering System:

• No loose, worn, bent, damaged, or missing parts
• Grab steering mechanism to test for looseness

Windshield:

• No damage; clean if dirty
• Wiper arms have proper spring tension
• Wiper blades not damaged, rubber not stiff, securely attached

Lights and Reflectors:

• Parking, clearance, ID lights clean, operating, proper color (amber)
• Reflectors clean, proper color (amber)
• Right front turn signal operating, proper color (amber or white)

Right Side

Right Front: Same checks as left front

Right Fuel Tank(s):

• Securely mounted
• Not damaged or leaking
• Fuel crossover line secure
• Adequate fuel
• Caps on and secure

Rear of Engine (visible portion):

• Not leaking

Transmission:

• Not leaking

Exhaust System:

• Secure, not leaking
• Not touching wires, fuel, or air lines

Frame and Cross Members:

• No bends or cracks

Air/Electrical Lines:

• Secured against snagging, rubbing, wearing

Spare Tire (if equipped):

• Securely mounted
• Proper size, properly inflated

Right Rear

Wheels and Tires:

• Condition of wheels and rims
• Tires properly inflated (minimum 2/32" tread)
• Tires not touching each other
• No cuts, bulges, objects between duals
• Tires same type (not mixed radial and bias)
• Tires evenly matched sizes

Suspension:

• Springs, hangers, shackles, u-bolts condition
• Axle secure
• Shock absorber condition

Brakes:

• Brake adjustment
• Brake drum or disc condition
• Hose condition (no rubbing wear)

Lights and Reflectors:

• Side-marker lights operating, proper color (red at rear, amber elsewhere)
• Reflectors clean, proper color

Rear of Vehicle

Lights:

• Rear clearance and ID lights clean, operating, red
• Reflectors clean, red
• Taillights clean, operating, red
• Right rear turn signal operating, proper color
• License plate present, clean, secured

Other:

• Splash guards present, not damaged, not dragging
• Cargo doors securely closed, latched/locked

Cargo (Trucks):

• Properly blocked, braced, tied, chained
• Tailboard up and secured
• Canvas/tarp secured (not blocking mirrors or lights)

Left Side

Same checks as right side, plus:

Battery (if not in engine compartment):

• Battery box securely mounted
• Box has secure cover
• Battery secured against movement
• Not broken or leaking
• Fluid at proper level
• Cell caps present and tight
• Vents clear

Step 6: Check Signal Lights

Get In and Set Up

1. Turn off all lights
2. Turn on stop lights (apply trailer hand brake or have helper press brake pedal)
3. Turn on left turn signal

Get Out and Check

• Left front turn signal clean, operating, proper color (amber or white)
• Left rear turn signal clean, operating, proper color
• Both stop lights clean, operating, proper color (red, yellow, or amber)

Get Back In

1. Turn off lights not needed for driving
2. Check for all required papers, permits
3. Secure loose articles in cab
4. Start engine

Step 7: Start Engine and Check Brakes

Test Hydraulic Brakes for Leaks

1. Pump brake pedal three times
2. Apply firm pressure
3. Hold for five seconds
4. Pedal should NOT move

Warning: If pedal moves, there may be a leak. Get it fixed before driving.

Test Parking Brake

1. Fasten safety belt
2. Set parking brake (power unit only)
3. Release trailer parking brake (if applicable)
4. Put vehicle in low gear
5. Gently pull forward against parking brake
6. Brake should hold vehicle

Repeat with trailer brake set and power unit brake released (if applicable).

Test Service Brake Stopping Action

1. Drive forward at about 5 mph
2. Push brake pedal firmly
3. Check for:
   • Vehicle pulling to one side (indicates brake trouble)
   • Unusual pedal feel
   • Delayed stopping action

Important: If anything is unsafe, get it fixed. Operating an unsafe vehicle violates federal and state law.

Pro Tips for the CDL Inspection Test

• Touch and name every item—examiners want to see you physically inspect
• Explain WHY you're checking each item
• Use the same sequence every time so you don't forget items
• Speak clearly so the examiner can hear your explanations
• Take your time—rushing causes mistakes

Common Mistakes to Avoid

Mistake 1: Skipping Items Every item matters. Skipping even "obvious" checks costs points. Follow the complete sequence every time.

Mistake 2: Not Explaining WHY Just naming parts isn't enough. Explain what you're looking for: "I'm checking the tires for proper inflation, cuts, bulges, and adequate tread depth."

Mistake 3: Forgetting Emergency Equipment Many applicants forget to check for triangles, fuses, and fire extinguisher. These are required items.

Mistake 4: Not Testing Controls Actually test the horn, wipers, and lights—don't just look at them.

Frequently Asked Questions

Q: How long does the vehicle inspection test take?

A: A thorough inspection takes 30-45 minutes. During the CDL test, you'll complete a portion of the full inspection. Practice until you can perform each step confidently without rushing.

Q: What if I find a defect during the test?

A: Point out the defect to the examiner. Finding actual problems shows you know what to look for. The examiner evaluates your inspection skills, not the vehicle's condition.

Q: Do I have to memorize everything?

A: Yes, for the test. In real practice, you can use a checklist. But the CDL test requires demonstrating knowledge from memory. Practice until the sequence becomes automatic.

Q: What's the most commonly missed item?

A: Emergency equipment (triangles, fire extinguisher, fuses), ABS indicator light check, and steering mechanism play test are frequently missed.

Q: How do I check steering mechanism looseness?

A: Grab the steering components and physically test for play. Steering wheel play over 10 degrees (about 2 inches on a 20-inch wheel) indicates problems.

Next Steps

After mastering the inspection:

1. Practice until you can complete the inspection without notes
2. Time yourself—aim for consistent, thorough completion
3. Have someone quiz you on WHY each check matters
4. Review specific defects that put vehicles out of service

Ready to test your knowledge? Start practicing with our Vehicle Inspection questions.

See our guides on Air Brake Inspection (Section 5) and Combination Vehicle Inspection (Section 6) for additional requirements.