CDL Mile

Kentucky CDL Air Brakes practice test

The Air Brakes test covers Section 5 of the Kentucky CDL Manual and is required if your vehicle has air brakes (1.1.1, p. 1-5). It has 25 questions (front section, p. 3). Skip or fail it and your CLP or CDL carries the L restriction, no air brakes (p. 1-3).

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Key facts

Pass mark80% on this test (25 questions)
Who takes itAnyone whose vehicle has air brakes, including air over hydraulic
CoversSection 5: air brake parts, dual systems, inspection, use
If you skip itRestriction L: no air-brake vehicles

Topics

What the Air Brakes test covers

Parts of an air brake system41 questions · manual §5.1→Dual air brake systems12 questions · manual §5.2→Inspecting air brakes24 questions · manual §5.3→Using air brakes24 questions · manual §5.4→

Questions drivers ask

What is on the Kentucky CDL air brakes test?
25 questions from Section 5 of the Kentucky CDL Manual: the parts of an air brake system, dual air brake systems, inspecting air brakes and using air brakes. You must take it if your vehicle has air brakes.
Source: Kentucky CDL Manual (March 2025), Section 5; Kentucky CDL Manual (March 2025), front section, p. 3
What does the L restriction mean on a Kentucky CDL?
No air brakes: you may not drive a commercial vehicle with any type of air brakes. It is added if you skip or fail the air brakes knowledge test, or take the skills test in a vehicle without air brakes.
Source: Kentucky CDL Manual (March 2025), p. 1-3

Sources

Kentucky Commercial Driver's License Manual, version March 2025, Kentucky State Police. Page references are to its printed page numbers. CDL Mile is independent and not affiliated with Kentucky State Police.

Updated for the March 2025 Kentucky CDL manual. Last checked November 5, 2026.

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