Missouri Air Brakes Test — Quick Facts
FormatWritten knowledge test
Questions25 questions
Passing score80% (20/25)
Min. age (intrastate / interstate)18 / 21
CLP hold before skills test14 days min
Government feeSee Missouri DMV →
Start the Free Missouri Air Brakes Test →
25 questions · one per page · your progress saves automatically
Missouri Air Brakes Practice Tests
4 full practice tests, each with 25 questions drawn from the Missouri CDL question bank. Your score and progress save as you go.
About the Missouri Air Brakes Test
In Missouri, passing the Air Brakes test removes the L restriction so you can drive a commercial vehicle equipped with air brakes. It covers the dual air system, low-air warnings, spring brakes, and the proper inspection and leakage checks.
PM
From Pedro, behind the wheelEvery truck I've driven runs air brakes. The test is less about theory than the checks before you roll — the static leakage test and the order of the warnings trip people up. Learn that sequence cold.
What Test-Takers Miss Most
- 1Naming the parts of the air brake system
- 2The leakage check and warning thresholds
- 3Brake fade from riding the brakes downhill
Missouri CDL Requirements & Fees
Missouri follows the federal CDL framework: a minimum age of 18 for intrastate driving and 21 for interstate, a commercial learner's permit you must hold at least 14 days before the skills test, and the 80% passing standard. License fees and retake rules are set by Missouri and change from time to time, so check the official source below for current amounts before you go in.
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Official Missouri CDL Handbook & FeesCurrent requirements, fees, and the manual this test is based on
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Frequently Asked Questions
How many questions are on the Missouri CDL Air Brakes test?
The Air Brakes test has 25 questions, and you need 20 correct to pass at the 80% threshold used across the U.S. under FMCSA standards. Exact counts can vary slightly by state, so confirm with the Missouri CDL handbook.
What score do I need to pass in Missouri?
You need 80% — that's 20 of 25 questions correct on the Air Brakes test.
How much does a Missouri CDL cost?
CDL fees are set by Missouri's licensing agency and change periodically, so we don't quote a figure that could go stale. Check current amounts on the official Missouri CDL page.
Is this Missouri practice test free and accurate?
Yes — it's completely free, based on the Missouri CDL handbook, and written and verified by Pedro Marin, an active CDL holder. No registration required.
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