Free Wyoming DMV CDL — Air Brakes Practice Test 2026
The Wyoming CDL — Air Brakes knowledge test has ~25 questions, and you need ~20 correct (80%) to pass. Practice free with questions written from the official Wyoming driver handbook — every one has a clear explanation, and you can retake as often as you like with no sign-up.
Content reviewed against official driver handbooks · August 12, 2026
What's on the Wyoming written test
The Wyoming CDL — Air Brakes knowledge test has ~25 questions; you need ~20 correct (80%) to pass.
Based on the official Wyoming exam format — always confirm current details with your state DMV.
Practice by topic
Focus on one area at a time — each topic has its own set of Wyoming practice questions.
Following distance, scanning, blind spots, using your lights, and the habits that prevent crashes and keep you in control.
Legal and illegal parking, colored curbs, distances from hydrants and crossings, and how to park safely on hills.
What to do when things go wrong — brake failure, tire blowouts, skids, and stalling on railroad tracks.
How to pass the first time
- Read the official Wyoming driver handbook at least once before test day.
- Practice by topic to find your weak spots, then fix them.
- Take full-length practice tests until you pass comfortably every time.
- Read every explanation — understanding beats memorizing.
Wyoming CDL — Air Brakes test — frequently asked questions
How many questions are on the Wyoming CDL — Air Brakes test?
The Wyoming CDL — Air Brakes knowledge test has ~25 questions, and you need ~20 correct (80%) to pass. Our practice tests mirror that format.
How many questions can I miss on the Wyoming CDL — Air Brakes test?
You can miss up to ~5 of the ~25 questions and still pass — you need ~20 correct, which is 80%.
Can I retake the practice test?
Yes — practice as often as you like, completely free. The questions and answer choices are shuffled each time.
Can I take the Wyoming practice test in Spanish?
Yes. Every question here is available in English and Spanish — switch languages anytime. Many states also offer the real knowledge test in languages other than English; confirm what Wyoming offers with your DMV.
Can I practice on my phone?
Yes. The practice tests work in any mobile or desktop browser — no app or sign-up needed — so you can study anywhere.
Are these the real DMV test questions?
No. Our questions are original, written from the current official Wyoming driver handbook to match the real test's topics and style. We are not affiliated with any DMV or government agency.
What's the best way to study?
Read the Wyoming driver handbook, practice by topic to target weak areas, and finish with full-length tests until you consistently pass.
Other Wyoming practice tests
Take the CDL — Air Brakes test in another state
Every Wyoming question is written from the official Wyoming driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free
Wyoming CDL — Air Brakes questions with answers
20 sample questions from the Wyoming CDL — Air Brakes question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
Show all 20 questions with answers
1. Section 11M explains why the air lines running to a trailer are inspected. What does it say a low air condition in those lines will cause?
Correct answer: The trailer's spring brakes to apply suddenly
According to Section 11M, low air to the trailer makes its spring brakes apply suddenly, which can mean loss of control and a crash. It adds that losing air to the trailer costs the towed unit some or all of its braking.
Source: Wyoming Commercial Driver License Manual — Section 11M.6.1, Air and Electric Lines / Connectors
2. Which pairing of a part and its standard matches the Step 5 walk-around check in Section 5?
Correct answer: Air hoses to the brake chambers: not cut, and not worn from rubbing
Hoses to the brake chambers must not be cut or worn from rubbing. Linings must not be loose, soaked with oil or grease, or dangerously thin; mechanical parts must all be in place and unbroken; and drum or disc cracks may not run longer than half the friction area's width.
Source: Wyoming Commercial Driver License Manual — Section 5.3.2, During Step 5 Walk around Inspection
3. Wyoming's manual lists situations in which a written test and a commercial learner's permit (CLP) are required. Which of these is on that list?
Correct answer: Removing the air brake restriction "L" from a CDL
Wyoming requires a written test and a new CLP in several situations, and one of them is an applicant removing the "L" air brake restriction; removing the air over hydraulics restriction is listed with it. Upgrading a license class or adding an endorsement is on the same list.
Source: Wyoming Commercial Driver License Manual — Wyoming Specific CDL Information, Required Tests
4. Section 5 describes more than one kind of parking brake control. Which pairing of a control and its purpose matches the manual?
Correct answer: Modulating control valve: applying the spring brakes gradually if the service brakes fail
A modulating valve lets the driver bring the spring brakes on a little at a time, which gives control if the service brakes fail. The spring-loaded valve on a dual parking control is the one that uses a separate air tank to release the spring brakes so the vehicle can be moved in an emergency.
Source: Wyoming Commercial Driver License Manual — Section 5.1.15, Parking Brake Controls
5. Going by the total stopping distances on the chart in Wyoming's Section 5, how much shorter is a stop from 45 mph than a stop from 55 mph?
Correct answer: 141 feet
The chart totals 451 feet at 55 mph and 310 feet at 45 mph, a difference of 141 feet. Ten miles per hour takes almost a third off the distance.
Source: Wyoming Commercial Driver License Manual — Section 5.4.4, Stopping Distance
6. Air is leaking away steadily as you drive a straight truck. According to the figures in Wyoming's Section 5, in what order do things happen as the pressure falls?
Correct answer: The low air warning comes on before 60 psi; the spring brakes come fully on somewhere between 20 and 45 psi
The warning has to come on before tank pressure drops below 60 psi, and tractor and straight truck spring brakes come fully on when pressure reaches the 20 to 45 psi range. The gap between the two is the driver's chance to stop while the brakes can still be controlled.
Source: Wyoming Commercial Driver License Manual — Section 5.1.14, Spring Brakes
7. You are about to pull out in a truck with a dual air system. The primary gauge reads 105 psi and the secondary reads 90 psi. Are you ready to drive?
Correct answer: No, both systems should build to at least 100 psi first
The manual tells drivers of dual-system vehicles to wait until the compressor has brought both the primary and the secondary systems up to at least 100 psi. Here the secondary system is still short.
Source: Wyoming Commercial Driver License Manual — Section 5.2, Dual Air Brake
8. You drive an air-braked truck that is small enough that operating it does not take a CDL. According to Section 5 of Wyoming's manual, do you need an air brake endorsement for it?
Correct answer: No, the endorsement is needed only when the vehicle itself requires a CDL
Section 5 opens by noting that the air brake endorsement applies only where the vehicle needs a CDL to begin with. Drivers of CDL-class trucks, buses and air-braked trailers are the ones told to study the section.
Source: Wyoming Commercial Driver License Manual — Section 5, Air Brakes
9. Section 5 describes the parking brake control on newer vehicles as a yellow knob shaped like a diamond. What wording does it say the knob carries?
Correct answer: Parking brakes
Section 5 says the newer control carries the label "parking brakes." Pulling it out applies the parking brakes, and pushing it in releases them.
Source: Wyoming Commercial Driver License Manual — Section 5.4.8, Parking Brakes
10. Between 15 and 55 mph on the chart in Wyoming's Section 5, which figure grows faster: driver reaction distance or vehicle braking distance?
Correct answer: Vehicle braking distance, which rises from 29 to 390 feet
Driver reaction distance goes from 17 feet at 15 mph to 61 feet at 55 mph, less than four times as far. Vehicle braking distance goes from 29 to 390 feet, more than 13 times as far, which is why speed matters so much to stopping.
Source: Wyoming Commercial Driver License Manual — Section 5.4.4, Stopping Distance
11. If a driver ignores a low air warning, falling pressure will eventually bring the spring brakes on by themselves. Which pairing of vehicle and risk matches the manual?
Correct answer: Heavily loaded vehicle: a long stopping distance, because spring brakes do not act on every axle
A heavy vehicle takes a long way to stop on spring brakes alone, since they are not on all axles. A lightly loaded vehicle, or any vehicle on a slick road, may instead skid out of control, so the manual says to stop while there is still air for the foot brakes.
Source: Wyoming Commercial Driver License Manual — Section 5.4.7, Low Air Pressure
12. Which pairing of a pressure figure and what happens there matches Wyoming's Section 5?
Correct answer: Usually 150 psi: the safety relief valve opens
The safety valve is normally set to open at 150 psi. Roughly 100 and 125 psi are the governor's cut-in and cut-out levels, 60 psi is the low air warning mark, and spring brakes come fully on between 20 and 45 psi.
Source: Wyoming Commercial Driver License Manual — Section 5.1, The Parts of an Air Brake System
13. A Wyoming applicant fails one version of the air brakes written test in the morning and a different version that afternoon. May the applicant sit the morning's version again before the day is over?
Correct answer: No, any one version may be taken only once in a day
Wyoming lets an applicant who fails one version of a written test try another version the same day, but no single version may be taken twice that day. Only the test that was failed has to be retaken.
Source: Wyoming Commercial Driver License Manual — Wyoming Specific CDL Information, Required Tests
14. Section 11M warns that an "unsafe act" during the vehicle inspection test may bring an automatic failure. Which example does it give?
Correct answer: Forgetting to set the parking brake
Section 11M's example of an unsafe act is forgetting to set the parking brake, and it says the examiner may end the test over one. Using the section's checklist and asking for clarification are both allowed.
Source: Wyoming Commercial Driver License Manual — Section 11M, Failure to Follow Instructions or Unsafe Act
15. The stopping distance chart in Wyoming's Section 5 gives a total of 375 feet at 50 mph. Which two figures on that row add up to it?
Correct answer: 55 feet of driver reaction distance and 320 feet of vehicle braking distance
At 50 mph the chart lists 55 feet of driver reaction distance and 320 feet of vehicle braking distance, for 375 feet in all. The 73 feet on that row is how far the rig travels in one second.
Source: Wyoming Commercial Driver License Manual — Section 5.4.4, Stopping Distance
16. You are driving a large bus when the low air warning comes on, yet the gauge still reads a little above 80 psi. Does that mean the warning device is faulty?
Correct answer: Not necessarily; on large buses the warning commonly signals at 80 to 85 psi
The manual notes that on large buses the low pressure warning commonly signals at 80 to 85 psi, well above the 60 psi mark it gives for other vehicles. A warning at that reading is what the manual describes, and it still means stopping and parking safely.
Source: Wyoming Commercial Driver License Manual — Section 5.1.11, Low Air Pressure Warning
17. The air brake section adds its own items to the seven-step inspection method described in Section 2. At which steps do those added items come?
Correct answer: Steps 2, 5 and 7
The extra checks come during Step 2 (the air compressor drive belt in the engine compartment), Step 5 (slack adjusters, drums, linings and hoses on the walk-around) and Step 7 (the final air brake check).
Source: Wyoming Commercial Driver License Manual — Section 5.3, Inspecting Air Brake Systems
18. Two entries on Wyoming's list of restriction codes concern air brakes. How does the list word code L?
Correct answer: Vehicle without air brakes; CDL only
Wyoming's restriction code list gives L as "Vehicle without air brakes; CDL only." The other air brake entry is Z, worded "No full air brake; CDL only," while E and O deal with manual transmissions and tractor-trailers.
Source: Wyoming Commercial Driver License Manual — Wyoming Specific CDL Information, Restriction codes
19. For the parking brake check in Section 11M, you engage the parking brake and gently pull forward against it. What does the manual have you do with the service brake first?
Correct answer: Take your foot off it
With the parking brake engaged, you remove your foot from the service brake and then pull forward gently. That way the parking brake alone is what keeps the vehicle from moving.
Source: Wyoming Commercial Driver License Manual — Section 11M.1.1, Parking and Trailer Brake Check
20. On the stopping distance chart in Wyoming's Section 5, vehicle braking distance is 29 feet at 15 mph. What does the chart list at 30 mph?
Correct answer: 115 feet
The chart gives 115 feet of vehicle braking distance at 30 mph. Doubling the speed roughly quadruples the braking distance; 148 feet is the total stopping distance on that row.
Source: Wyoming Commercial Driver License Manual — Section 5.4.4, Stopping Distance