MT CDL Air Brakes study guide
MT CDL Air Brakes · Work through your exam, one topic at a time.
The Montana CDL air brakes knowledge test is the written portion of the air brake endorsement requirement for drivers who operate vehicles equipped with air brake systems - typically Class A and Class B commercial vehicles such as tractor-trailers, dump trucks, buses, and heavy straight trucks. In Montana, as federally, you must pass the air brakes knowledge test to have the air brake restriction removed from your CDL; without it, your license carries a restriction prohibiting you from operating air-braked vehicles. The MT CDL Air Brakes study guide has 7 sections and about 2,739 words.
01Air Brake System Components and Their Functions
This domain tests whether you can name each component of a vehicle air brake system, state the pressure at which it acts, and explain how it interacts with the rest of the system. Montana questions tend to be device-specific: which part does what, and what a given symptom points to.
417 words, about 2 min02Dual Air Brake System and Safety Features
The exam tests your understanding of the dual (split) system and the automatic protections built into it: the low pressure warning, the spring brakes, and the tractor protection valve. Expect questions on the order in which these act as pressure falls.
400 words, about 2 min03Pre-Trip Inspection of the Air Brake System
This domain covers the sequence a driver must actually perform before driving: draining tanks, testing for leaks, checking build rate, checking the governor, checking the warning devices, and checking the spring brakes. Examiners expect the correct order and the correct numbers.
370 words, about 2 min04Normal Driving with Air Brakes
This domain tests braking technique, the causes of brake fade, and how speed, weight, and grade change stopping distance. Montana's long mountain grades make this section practically important and frequently tested.
366 words, about 2 min05Emergency Braking and Brake Failure Procedures
The exam tests what you do when braking is degraded or gone: which controls to use, in what order, and what not to do. Answers are judged on the safe sequence, not just the final action.
371 words, about 2 min06Inspecting and Using Parking Brakes and Spring Brakes
This domain tests the parking brake control, the spring brake mechanism, and the rules for parking safely. Expect questions on the yellow knob's operation, on caging bolts, and on when not to set a parking brake.
425 words, about 2 min07Maintenance, Troubleshooting, and Out-of-Service Criteria
This domain tests whether you can diagnose common air brake faults and recognize the conditions that place a vehicle out of service. Questions mix symptom-matching with the roadside inspection rules.
390 words, about 2 min