Wyoming Air Brakes CDL Practice Test
Below are 25 exam-style questions for the Wyoming Air Brakes CDL knowledge test, modeled on the FMCSA-aligned content used by the Wyoming Department of Transportation. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.
- A Engine vacuum
- B Air pressure
- C Electrical current
- D Hydraulic pressure
- A Set both tractor and trailer parking brakes
- B Leave both released
- C Set only the trailer parking brake
- D Set only the tractor parking brake
- A Brake pad wear
- B Coolant temperature
- C When the air compressor will pump air into the storage tanks
- D Engine RPM
- A The compressor cuts out
- B Air pressure may drop slightly
- C Air pressure should remain unchanged
- D Air pressure increases
- A Test the parking brake
- B Drain the wet tank
- C Make pre-trip inspections
- D Use the trailer hand valve as a parking brake
- A 20 psi
- B 60 psi
- C Never; only the gauge needs to read it
- D 40 psi
- A Tractor brakes apply
- B Nothing happens
- C Trailer service brakes apply
- D Trailer spring brakes apply automatically
- A The transmission
- B The exhaust system
- C The electrical system
- D The engine, by belts or directly geared
- A Cool the air before it enters the brake chambers
- B Increase pressure
- C Remove moisture and contaminants from the compressed air
- D Replace governors
- A Pumping the brakes
- B Driving at 30 mph and slamming on the brakes
- C Listening to the air gauge
- D At about 5 mph, applying the brake firmly and feeling for pulling, sticking, or unusual feel
- A Free of dirt and damage and properly seated
- B Loose for easy connection
- C Coated with oil
- D Removed for inspection
- A Running at high RPM
- B In gear
- C Started and stopped repeatedly
- D Off, with brakes released for the first part
- A Wait for full system pressure before moving
- B Drive immediately
- C Pump the service brake five times
- D Drain the wet tank
- A Replace foundation brakes
- B Are required only on hazmat trailers
- C Help prevent wheel lockup but do not necessarily shorten stopping distance
- D Are optional and rarely installed
- A About 3 minutes in dual systems
- B It does not matter
- C Less than 30 seconds
- D 10 minutes
- A 5 psi per minute
- B 2 psi per minute
- C 3 psi per minute
- D 4 psi per minute
- A The trailer service brakes only
- B The parking brake
- C Both tractor and trailer brakes
- D The tractor service brakes only
- A A broken governor
- B A clogged air filter or worn compressor
- C All of the above
- D A leak in the brake system
- A Neither of the above
- B Locking the wheels by braking too hard
- C Driving too fast for conditions
- D Both of the above
- A Honking
- B Coasting in neutral
- C Using the trailer hand valve, then engine braking, then a runaway ramp if needed
- D Putting the transmission in reverse
- A 5 psi per minute
- B 1 psi per minute
- C 3 psi per minute
- D 2 psi per minute
- A There is no situation in which draining is wrong
- B The vehicle is in motion
- C You are about to begin a trip
- D It is full of moisture
- A Pumping them while parked
- B Listening for a hiss
- C Looking at the gauge
- D Releasing the parking brakes, moving the vehicle slowly forward, and applying the trailer hand valve
- A At the bottom only
- B In the middle of the descent
- C Before reaching the top, while still on level ground
- D Once a year
- A Show no signs of damage, leaks, or excessive wear
- B Be wrapped in tape
- C Have at least 5 splices each
- D Be coiled tightly under the truck
Study tips for the Wyoming Air Brakes exam
The Air Brakes portion of the Wyoming CDL exam is graded out of the bank of questions the Wyoming Department of Transportation draws from each year. While the exact bank is not published, every question is sourced from the Air Brakes chapter of the Wyoming CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.
Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Wyoming handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.
Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about Air Brakes.
Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Wyoming Department of Transportation will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.
Finally, keep your General Knowledge fundamentals sharp even when you're focused on the Air Brakes exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Wyoming General Knowledge practice test before scheduling the real exam.
Next steps
Missed more than four questions? Re-read the Air Brakes study guide and the matching chapter in the official Wyoming CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Wyoming Department of Transportation office.
Already comfortable with this endorsement? Drill another: WY General Knowledge · WY Combination Vehicles · WY Hazardous Materials · WY Passenger · WY School Bus · WY Tank Vehicle · WY Doubles / Triples
New to the CDL process in Wyoming? Read How to apply for a CDL in Wyoming for the document checklist and step-by-step timeline.