Air Brakes Pre Trip Inspection Script: Say It Word for Word

The air brake pre trip check has four parts: gauge and governor, leak test, low air warning, and spring brake pop-out. This page gives you the exact words to say and do for each one, with the psi numbers, and a free printable card you can tape to your dash.

The numbers come from the Virginia CDL manual (AAMVA 2026 edition) and federal rules. The words in quotes are ours. The manual does not give a fixed script, so use your own words if you like. Check your state's manual and your truck's own specs for your exact numbers.

Download the one page script card (PDF, free)

Looking for a Class A pre trip inspection checklist PDF? This card covers the air brake part of it, the part with the most numbers. The other steps are in our checklist guide at the end of this page. No email needed.

The numbers in one table

Two notes. The manual says to check the maker's specs, because trucks differ. And the old single air system (before 1975) has its own build up rule: 50 to 90 psi within 3 minutes with the engine at 600 to 900 rpm. Most trucks you test in are dual systems.

The script, step by step

Say each line out loud. Do the action as you say it. Point at the gauge, touch the pedal, and tell the examiner what you are checking and why. The manual says you get no credit for an item you do not name, point to and/or touch, and fully explain.

Step 1. Build air and check the gauge

Do: Set the parking brake. Chock the wheels if required. Start the engine and watch the gauge.

Say: "Parking brake is set. Wheels are chocked. I start the engine. My air gauge is working. I build air to the governor cut-out. It should stop at about 125 psi. Many trucks stop between 120 and 140 psi. I check my truck's own number."

Why: The governor stops the compressor when tank pressure reaches cut-out. If the needle never stops, the governor may need repair.

Step 2. Static leak test (brakes released)

Do: Make sure the system is fully charged. Turn the engine off. Release the parking brake (push it in). Watch the gauge for one minute.

Say: "Air is fully charged. Engine is off. Parking brake is released. I time one minute. I must lose less than 2 psi on a single vehicle, or less than 3 psi on a combination."

Step 3. Applied leak test (foot brake on)

Do: Turn the key back to ON (battery power). On a combination vehicle, release the tractor protection valve. Fully press the foot brake. Wait for the gauge to settle after the first drop. Then hold the brake for one minute.

Say: "Foot brake fully applied. The gauge has settled. I time one minute. I must lose no more than 3 psi on a single vehicle, or no more than 4 psi on a combination."

Why: A leak you do not fix can mean you lose your brakes while driving.

Step 4. Low air warning test

Do: Keep the key ON. Do not start the engine. Press and release the brake pedal again and again to lower the air. This is called fanning. Watch the gauge and listen.

Say: "I fan off the air. The low air warning must come on before 55 psi. I see the light and hear the buzzer. [Name the flag or wig wag if your truck has one.] It came on at ___ psi."

Why: Without a working warning you could lose air and not know it.

Step 5. Spring brake pop-out

Do: Keep fanning. Watch for the parking brake valve to pop out. On a combination vehicle, watch the tractor protection valve and the trailer valve too.

Say: "I keep fanning. The parking brake valve pops out between 20 and 45 psi. It popped at ___ psi. The spring brakes are now on. On a combination, the tractor protection valve and trailer valve close at the same time or before the truck valve."

Dual system tip: If your truck has a primary and a secondary system, say that there is a backup. The manual says the valves will not pop out from losing pressure in only one of the systems. If your valves do not pop out, listen for air leaving the system. That sound means the parking brakes came on.

Step 6. Rebuild air, cut-in and build up time

Do: Start the engine. Time how long the gauge takes to rise from 85 to 100 psi. Let it build to cut-out. Then, with the engine idling, press and release the brake pedal to lower the pressure until the compressor cuts in.

Say: "I start the engine and time the build up. On a dual air system it should go from 85 to 100 psi within 45 seconds. The air builds to cut-out and the needle stops. I lower the pressure with the brake pedal. The compressor cuts in at about 100 psi and the needle starts to rise. Both gauges are above 100 psi before I drive."

Step 7. Final brake checks

Do: With the parking brake set and full air, put the truck in a low gear and gently pull against the brake. Then wait for normal air, release the parking brake, roll forward slowly at about five mph and press the service brake firmly.

Say: "Parking brake holds in a low gear. I wait for normal air. I roll at about five mph and apply the service brakes firmly. I check for pulling to one side, an odd feel or a late stop."

3 mistakes that can fail you

1. Skipping or botching any of the four parts. The skills test sheet says that failing to explain and perform all four parts of the air brake check correctly will result in an automatic fail of the vehicle inspection test. The four parts are the gauge and governor cut-out, the leak test, the low air warning, and the emergency brake pop-out.
2. Doing it silently or without your truck's numbers. The manual says you must name, point to and/or touch, and fully explain what you are checking, or you get no credit. It also says you must know and describe your vehicle's manufacturer specs. A quiet check with no numbers is not enough.
3. An unsafe act or ignoring the examiner. The manual says an unsafe act, such as forgetting to set the parking brake, may be an automatic fail. So may not following the examiner's instructions. Set the brake first. Chock the wheels if required. Ask if you do not understand.

One more tip from the same sheet: for the leak test and the warning test, the key stays in the ON or battery position. Do not turn it all the way off.

How to practice

Here is how we would practice it if you were riding with us.

• Say it in your kitchen first. We would have you use a chair as the truck and a paper plate as the gauge. Say the words and the numbers out loud until they come easily.
• Use the card for the first week. Print it and tape it to your dash or clipboard. Then cover the numbers column and say them from memory.
• Learn the order, not just the numbers. Gauge, leak, warning, pop-out, rebuild. If you know the order, you will not skip a part.
• Time it on your phone. Run the one minute leak tests and the 45 second build up with a timer so you know how long they feel.
• Say it slowly. We say: talk at the speed of a calm radio voice. Examiners cannot give credit for what they cannot hear.
• ESL tip: Learn the six key words well: gauge, governor, leak, fan, warning, pop out. Write them in your own language next to the English.

If your leak loss is over the limit when you practice, that is a leak that has to be found and fixed before you drive. Tell your trainer. Do not keep practicing on a truck that loses more than the limit.

Want the big picture first? Read our CDL pre-trip inspection checklist for all seven steps, and our CDL air brakes test guide for the written test. Our air brake cheat sheet has the parts on one page. If you will pull a trailer, read the combination vehicles test guide. The CDL road test guide shows where the inspection fits in the full skills test. If you missed the air brake check, see what to do after a failed CDL road test.

Night-before card check

Run this check the night before your test.

1. Can you say the four parts in order with the card face down? Gauge and governor, leak, warning, pop-out.
2. Do you know the cut-out number of the exact truck you test in? Ask your school or the test site and write it in the blank on the card, because the manual says the number for your vehicle is the one that counts.
3. Can you run a full one minute leak test out loud, naming the starting psi, the ending psi and the loss, without losing your place?

If any answer is no, repeat only that part tonight, not the whole script. The easy way to lose points is to go silent while the gauge moves.

Fill in the blank method

Print the card and write three numbers in pencil for your test truck: cut-out psi, cut-in psi and the psi where its low air warning comes on. Then say "it came on at ___ psi" with the real number off the gauge. A number you read off the truck shows the examiner you are looking at the truck.

Try 10 free exam-style air brakes questions built from the manual.