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Posts published in “Air Brakes Practice Tests”


The Free CDL Air Brakes Practice Tests developed by CDL Digest each contain 25 multiple choice questions to help you pass the actual CDL Air Brakes Test on the first attempt. You must have a score of 80% (20 out of 25 questions) or better to pass. This test is required for any driver that will be operating a commercial motor vehicle (CMV) that is equipped with air brakes or an air over hydraulic braking system. Drivers who fail the CDL Air Brake Test or simply decide not to take it based on the type of commercial motor vehicle (CMV), must have an Air Brakes Restriction (L) on their commercial learner’s permit (CLP) or commercial driver’s license (CDL) (49 CFR 383.95).

Air Brakes can be added to a commercial learner’s permit (CLP) or commercial driver’s license (CDL).

CDL Air Brakes Practice Test 1

CDL Air Brakes Practice Test 2


Each Free Practice Test covers knowledge of the seven (7) areas all commercial motor vehicle (CMV) drivers operating vehicles equipped with air brakes must have as required by Federal Regulation (49 CFR 383.111(b)) as follows:

49 CFR 383.111(b)(1): General Air Brake System Terminology

49 CFR 383.111(b)(2): The Dangers of a Contaminated (dirt, oil, and moisture) Air Supply

49 CFR 383.111(b)(3): Dangers of Severed or Disconnected Air Lines between the Power Unit (tractor) and the Trailer (semi-trailer)

49 CFR 383.111(b)(4): Dangers of Low Air Pressure

49 CFR 383.111(b)(5): Pre-Trip Inspection Procedures

49 CFR 383.111(b)(6): Enroute and Post-Trip Inspection Procedures

49 CFR 383.111(b)(7): Operating Procedures, such as Proper Braking Techniques, Antilock Braking Systems (ABS), Emergency Stopping Procedures, and Parking Brake.

The above listed CDL Air Brakes information for testing purposes can also be found in AAMVA’s “2005 CDL Test System (July 2010 or newer Version) Model Commercial Driver Manual”, which is made available at no cost at all 50 State Driver Licensing Agencies.

Section 5 of the CDL Manual covers the following topics for Air Brakes:

Air Brakes System Parts

Dual Air Brake Systems

Inspecting Air Brakes

Proper Use of Air Brakes

The source material used by CDL Digest to develop these practice test questions is very technical. It may be necessary for you to take the Practice Tests several times to make sure you have a thorough understanding of all the material before taking the actual CDL Air Brakes Test at your State Driver Licensing Agency.