ND CDL Air Brakes study guide
ND CDL Air Brakes · Work through your exam, one topic at a time.
The North Dakota commercial driving program is administered by the North Dakota Department of Transportation (NDDOT), whose website lists a Commercial section with pages for the Commercial Driver License (CDL), the Commercial Driver License Manual, how to apply for a CDL, how to renew a CDL, CDL Third Party Testing, and Hazardous Material Requirements. The air brakes knowledge test is the written component a candidate takes to be cleared for vehicles equipped with air brakes; it is separate from the general CDL knowledge test and from the skills test. The ND CDL Air Brakes study guide has 4 sections and about 1,500 words.
01Air Brake System Components and Function
This domain tests how an air brake system creates, stores, controls, and applies compressed air. Expect questions on the compressor and governor, reservoirs, valves, brake chambers, slack adjusters, and spring brakes-not just names, but what each part does when you press the treadle.
381 words, about 2 min02Inspecting and Testing Air Brake Systems (leak, low pressure warning, spring brake check)
This domain tests the pre-trip air-brake tests: leakage, low-pressure warning, compressor build-up, and governor operation. The exam expects a sequence and numeric limits, not just “check the brakes.” Park on level ground, chock wheels, and build pressure to governor cut-out (about 125 psi).
376 words, about 2 min03Normal Operating Procedures and Braking Technique
This domain tests how to use air brakes in everyday driving: pre-drive pressure, smooth application, downhill control, and parking. The exam favors the technique that keeps pressure up and brakes cool.
364 words, about 2 min04Emergency Procedures and Malfunction Response
This domain tests what to do when air pressure is lost, brakes fade, or a spring brake or trailer emergency system activates. The safe answer is almost always: stop safely, secure the vehicle, and do not continue until repaired.
379 words, about 2 min