California Pre-Trip Inspection

The pre-trip is the first part of your DMV skills test. You must pass it before you move to the Skills Test, and pass the skills test before you move to the Driving Test. DMV's current name for it is the Vehicle Inspection Test. Most people still call it the pre-trip, and so do we.

How You Are Scored

Think safety. Touch, point, and fully explain. For every safety-critical item you must name it, point to or touch it, and explain what you are inspecting it for. Naming the part alone does not earn credit.

• You will not have to crawl under the vehicle or reach into the engine.
• Set the parking brake and place the vehicle in neutral before you exit. Face the vehicle and keep three points of contact entering and exiting.
• Use wheel chocks during the inspection.
• You may carry the DMV checklist and check items off as you go. No writing or markings may be added to it beforehand.
• You will be asked to inspect one axle, but be ready to perform the same inspection on any axle on the vehicle.
• A vehicle with components marked or labeled by anyone other than the manufacturer cannot be used for the test.

Unsafe act. Forgetting to set the parking brake is the classic one. An unsafe act can end the test immediately. Safety of the driver, the examiner, and the testing area comes before everything else. If you do not understand an instruction, ask the examiner to repeat it.

In-Cab and Engine Start

Lighting Indicators

Confirm the dash indicators come on when the vehicle starts and when the matching switch is used:

• Left turn signal indicator
• Right turn signal indicator
• Four-way emergency flasher indicator
• High beam headlight indicator
• ABS indicator. On a combination vehicle, the trailer ABS lamp on the rear driver's side should come on and then go out
• DEF indicator, if the vehicle has one

Say it out loud: these are dash indicators only. The actual turn signals, flashers, and high beams get demonstrated separately during the lights operations check.

Emergency Equipment

• Three red reflective triangles
• Six spare electrical fuses, or three liquid burning flares. If the vehicle runs on circuit breakers instead of fuses, tell the examiner that and point out the breakers
• Fire extinguisher — properly rated, fully charged, securely mounted

Windshield, Mirrors and Monitoring Devices

• Windshield is clean and securely mounted, no cracks or flaws, nothing blocking your view, no stickers except an inspection sticker
• Mirrors are clean and adjusted to you from inside the cab
• If the vehicle has cameras or rear and side view monitors, they are clean, working, viewable from inside, and adjusted

Wipers, Washers, Heater, Defroster, Horns

These are demonstrated, not just described. Operate each one:

• Wiper arms and blades securely mounted, not damaged. Turn them on and off
• Washer fluid present. Activate the washers
• Heater and defroster — operate the controls and confirm they work
• Air horn and electric horn, whichever the vehicle has

Air Brake Check

Numbers to Know Cold

• Governor cutout — 120 to 140 PSI
• Applied air leakage — no more than 4 PSI in one minute on a combination vehicle, 3 PSI on a single vehicle or a trailer without air brakes
• Low air warning — activates before pressure drops below 55 PSI, or the level the manufacturer specifies
• Spring brake pop-out — no less than 20 PSI, no more than 45 PSI

If your vehicle's specifications differ from these, it is your responsibility to know them and explain them to the examiner.

Setting Up

• Apply the truck and trailer parking brakes — pull both knobs out
• Confirm the vehicle is in neutral
• Announce "clear"
• Chock the wheels
• Turn the key to auxiliary and let the gauges sweep fully
• Start the truck
• Confirm the ABS lamp works — in the cab and on the side of the trailer
• Identify which gauge you are reading, primary or secondary

Part 1 — Air Gauge and Governor Cutoff

Build air pressure to governor cutout. Call out the number the needle stops rising at. It should land between 120 and 140 PSI.

Part 2 — Applied Air Leakage Test

Shut the engine off. Turn the key back to auxiliary. Release the truck and trailer brakes and wait for the air to stop rushing. Put your foot on the brake and hold it. Let the gauge settle, identify the PSI it settled on, then announce:

"I am performing the applied air leakage test. I should not lose more than 4 PSI in one minute on a dual system, 3 PSI on a single system. I am starting my timer."

Hold the brake for one full minute, then declare how much pressure you lost.

Part 3 — Low Air Warning

Announce that the low air warning should activate no lower than 55 PSI. Fan the brakes until the buzzer and light come on, and call out the PSI it activated at.

Part 4 — Emergency Brakes

Keep fanning. Announce that the parking brakes should pop out no less than 20 and no more than 45 PSI. Call out the number they pop at, and confirm both knobs popped. On an air-operated trailer, the tractor protection valve and trailer brake valve should close at the same time as the truck valve or before it.

If the valves on your vehicle are not designed to pop out, listen for air discharging and explain that to the examiner. If the vehicle has a backup air system, explain that the valves will not pop.

Hydraulic Brake Check — Vehicles Without Air Brakes

Same rule: explain and demonstrate it correctly or the test ends. With the transmission in park, identify the normal height of the brake pedal, pump it three times, then hold it down for five seconds. The pedal should not sink after the initial application, and should feel firm with reserve travel left. Confirm any warning indicators and hydraulic power assist systems are working as the manufacturer specifies.

Parking, Trailer and Service Brake Checks

Three separate checks, performed in this order:

• Trailer brake. Truck parking brake released, trailer brake applied. Foot off the service brake. Put it in gear and tug gently against the trailer brake. This also confirms your coupling is holding.
• Parking brake. Truck parking brake applied, trailer brake released. Foot off the service brake. Tug gently forward and confirm the brake holds the vehicle.
• Service brake. Release both. Pull forward at no more than 5 mph, apply the foot brake and come to a complete stop. The vehicle should stop cleanly and not pull to either side.

Lights Operations Check

This one is inspected from outside the vehicle. Ask the examiner to assist. You stay in the cab with the parking brake set, auxiliary power on, and the window down. Speak loudly. Tell the examiner exactly which light you want checked, then operate it.

• Low beam headlights
• High beam headlights
• Left and right turn signals
• Four-way flashers
• Clearance and marker lights
• Tail lights
• Brake lights — on when applied, off when released

Front, sides, and rear. On a combination vehicle you only need to check the rear of the trailer. If you leave a light out, you do not get credit for it. Name every one.

Front of Vehicle and Engine Area

Engine off for this section.

Lenses

Light lenses and covers on the front are the proper color, clean, not broken, not missing. Clearance lights and turn signals amber. Headlights clear, not fogged, not broken, securely mounted.

Fluid Levels

Indicate where each is checked and that you would confirm the level sits between the add and full marks:

• Engine oil — identify the dipstick and say you would confirm it reads in safe operating range above the refill mark
• Coolant — reservoir securely mounted, filled above the refill mark, cap tight, not leaking
• Power steering fluid — same
• Brake fluid — hydraulic brake vehicles only
• Windshield washer fluid — filled, cap tight, hose not cut or leaking

Never remove a radiator cap on a hot engine.

Fluid and Air Leaks

• No puddles on the ground
• No dripping around or under the engine and transmission
• Hoses and air lines in good condition, no leaks
• Truck and trailer sitting level, no lean front to back or side to side

Steering System

• Steering box securely mounted, not leaking
• Steering hoses and connections not cracked, worn, or leaking
• No missing nuts, bolts, or cotter keys anywhere in the steering system
• Connecting links, arms, and rods from the steering box to the wheel — not worn or cracked, joints and sockets not worn or loose

Steering Axle

Be ready to perform this same inspection on any axle on the vehicle.

Tires — Remember ICD

• Inflation. You must say you would check it with a tire gauge. Kicking the tire or hitting it with a mallet earns you nothing. Valve stems accessible, valve caps present, stems not damaged
• Condition. No cuts or damage exposing body plies in the tread or sidewall. No bumps or bulges. Evenly worn. No mismatched diameters on duals. No recaps on the steer axle
• Depth. Measured with a tread depth gauge on all major grooves — no less than 4/32 on steering axle tires, no less than 2/32 on all other tires

If the vehicle has an automatic tire inflation system or tire pressure monitoring system with hoses on the valve stems, say that pressure is monitored and adjusted automatically and confirm the system is working.

Rims and Wheels

• Not cracked, bent, or damaged. No welding repairs
• No rust trails indicating the rim is loose
• Studs and bolt holes not elongated or out of round

Lug Nuts

All present, all tight, no broken studs, no rust trails or shiny threads showing looseness.

Springs, Air Bags and Shocks

• Leaf springs not missing, shifted, cracked, or broken. Spring mounts, hangers, shackles and U-bolts not cracked, broken, or missing parts
• Coil springs not broken or distorted, mounts intact
• Air ride suspension secure, not damaged, not leaking
• Shock absorbers secure, not damaged, not leaking
• Vehicle sitting level

If suspension components are not visible or accessible, tell the examiner so, confirm the vehicle is sitting level, and note that a lean can indicate a suspension problem.

Brake Lines, Hoses and Leaks

• Hoses and lines securely mounted, not cracked, worn, frayed, cut, or leaking
• All couplings and fittings secure
• On electric brakes, electric lines secure and casing not worn or cracked

Brake Contaminates

Where accessible, check the brake linings or pads and the drum or disc for grease, oil, or other contamination. Contaminated brakes lose friction and can start a fire.

Side of Vehicle

• Lenses and reflectors. Proper color, clean, not broken, not missing — on the vehicle and the trailer
• Mirrors and monitoring devices. Clean, not cracked, brackets not bent, mounted securely, no missing parts
• Battery and electrical. Batteries secure if visible, connections tight without excessive corrosion, cables and lines secure and not cracked or worn, battery box cover secure. If the batteries are not visible or accessible, say so
• Fuel tanks and DEF tank. Securely mounted, straps secured to the frame with the rubber intact, caps tight, no leaks from tanks, caps, or lines. DEF above one-eighth
• Frame. Straight, no cracks, no broken welds, no extra holes, no damage. No cracks, breaks, or holes in the cargo area or floor. Trailer tandem release lever and pins secure

Combination Vehicles and Coupling

Air and Electric Lines and Connectors

You must inspect the connections on both the power unit and the trailer to get credit.

• Connectors seated, sealed, locked in place, free of damage, safety latch present and not broken
• Air hoses and electrical lines not cut, cracked, chafed, spliced, taped, or worn — no steel braid or conductor showing through
• Lines not tangled, crimped, pinched, dragging, or resting on the catwalk
• Listen for air leaks

Fifth Wheel Coupling

• Skid plate — securely mounted to the platform, no cracks, breaks, or excessive wear, properly greased
• Platform — not cracked or broken, no missing bolts or nuts, secured to the truck frame
• Kingpin — in place, not bent, damaged, or worn
• Apron — visible portion not bent, cracked, or broken, secured to the trailer frame, properly greased
• Gap — the apron rests flat on the skid plate. There should be no gap
• Locking jaws — look into the gap and confirm the jaws are fully closed around the kingpin with no play
• Release arm — in the engaged position, safety latch or lock in place, no free play
• Sliding fifth wheel locking pins — undamaged and fully engaged

Pintle Hook or Tow Hitch Combinations

If your vehicle uses a pintle hook or another coupling system, inspect the hook or hitch securely mounted to the frame, no loose or missing bolts, nuts, pins, brackets or clamps, no cracks, breaks, or excessive wear. Check the drawbar ring or coupler is not bent, twisted, or worn and is secured to the tongue with no loose bolts, broken welds, or cracks. Check the tongue for dents, twists, cracks, and broken welds. Confirm safety pins and cotter pins are in place, and that safety cables or chains are secure, crossed, free of kinks and excessive slack, with breakaway cables engaged.

Coupling systems vary. If yours is a type not covered above, describe to the examiner how it works and what you are inspecting.

Trailer and Rear

• Landing gear. Fully raised, no missing parts, crank handle secured, support frame and landing pads undamaged, legs straight, feet present. Legs will clear the truck frame and mud flaps while turning. If power operated, no air or hydraulic leaks
• Reflective tape. Present on the sides and rear, clean, visible, affixed securely
• Rear lenses and reflectors. Proper color, clean, not broken, not missing. Red at the rear

Official DMV Documents

Read these directly from the state. They are the controlling documents for your test.

Vehicle Inspection Checklist (PDF)

CDL Handbook Modernization Supplement (PDF)

California Commercial Driver Handbook (PDF)