Alaska Air Brakes CDL Practice Test
Below are 25 exam-style questions for the Alaska Air Brakes CDL knowledge test, modeled on the FMCSA-aligned content used by the Alaska Division of Motor Vehicles. 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 Worn-out hoses
- B Too much air pressure
- C Cold weather
- D Heat from continuous brake use on long downgrades
- A They reduce stopping distance significantly without normally causing skids on dry pavement
- B Federal law mandates them as decorative
- C They look balanced
- D They make steering easier
- A Locking the wheels by braking too hard
- B Both of the above
- C Driving too fast for conditions
- D Neither of the above
- A They control trailer height
- B Out-of-adjustment slack adjusters can result in brakes that do not work properly
- C They affect engine performance
- D They are decorative
- A Electrical current
- B Hydraulic pressure
- C Engine vacuum
- D Air pressure
- A There is no situation in which draining is wrong
- B It is full of moisture
- C You are about to begin a trip
- D The vehicle is in motion
- A Look at the dashboard light
- B Disconnect the trailer
- C Pump the brake to fan down the pressure and verify the warning activates before pressure drops below 60 psi
- D Drain the wet tank only
- A Apply the parking brake
- B Light, intermittent braking with engine braking and a low gear
- C Coast in neutral
- D Heavy continuous braking
- A Drain the wet tank
- B Test the parking brake
- C Make pre-trip inspections
- D Use the trailer hand valve as a parking brake
- A Drive shaft
- B Set of brake chambers
- C Air compressor
- D Engine
- A Be coated with oil
- B Have small cracks
- C Be glowing red after stops
- D Be free of cracks longer than half the width of the friction area
- A When the air compressor will pump air into the storage tanks
- B Coolant temperature
- C Brake pad wear
- D Engine RPM
- A Setting the parking brake, releasing the service brake, and gently trying to move the vehicle
- B Doing nothing — the dashboard light is enough
- C Driving over a curb
- D Pressing the service brake while parked
- A The tractor service brakes only
- B Both tractor and trailer brakes
- C The trailer service brakes only
- D The parking brake
- A Listening for a hiss
- B Pumping them while parked
- C Looking at the gauge
- D Releasing the parking brakes, moving the vehicle slowly forward, and applying the trailer hand valve
- A Pumping the brakes
- B At about 5 mph, applying the brake firmly and feeling for pulling, sticking, or unusual feel
- C Listening to the air gauge
- D Driving at 30 mph and slamming on the brakes
- A Check the brake light visibility
- B Drain the wet tank
- C Disable the warning lamp
- D Allow the system to reach operating pressure before driving
- A Steering wander
- B Tire blowouts
- C Engine overheating
- D Wheel lockup during emergency braking
- A Nothing happens
- B Trailer spring brakes apply automatically
- C Tractor brakes apply
- D Trailer service brakes apply
- A Pump rapidly and lightly
- B Use only the parking brake
- C Use stab braking — apply hard, release when wheels lock, re-apply
- D Press as hard as possible and hold
- A Are required only on hazmat trailers
- B Are optional and rarely installed
- C Help prevent wheel lockup but do not necessarily shorten stopping distance
- D Replace foundation brakes
- A Coasting in neutral
- B Honking
- C Putting the transmission in reverse
- D Using the trailer hand valve, then engine braking, then a runaway ramp if needed
- A At the bottom only
- B In the middle of the descent
- C Once a year
- D Before reaching the top, while still on level ground
- A Stab the brakes
- B Release the brakes immediately
- C Pump rapidly
- D Press as hard as possible and hold
- A It is bad luck
- B It will reduce engine power
- C It can damage the rubber seals
- D It violates federal weight law
Study tips for the Alaska Air Brakes exam
The Air Brakes portion of the Alaska CDL exam is graded out of the bank of questions the Alaska Division of Motor Vehicles draws from each year. While the exact bank is not published, every question is sourced from the Air Brakes chapter of the Alaska 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 Alaska 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 Alaska Division of Motor Vehicles 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 Alaska 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 Alaska 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 Alaska Division of Motor Vehicles office.
Already comfortable with this endorsement? Drill another: AK General Knowledge · AK Combination Vehicles · AK Hazardous Materials · AK Passenger · AK School Bus · AK Tank Vehicle · AK Doubles / Triples
New to the CDL process in Alaska? Read How to apply for a CDL in Alaska for the document checklist and step-by-step timeline.