Free Practice Questions for LA CDL Air Brakes
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7 Job WikiSample LA CDL Air Brakes Practice Questions
Try these sample questions to review concepts for the LA CDL Air Brakes exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 220+ question experience with AI tutoring.
1According to the Louisiana CDL Manual, an air brake system is really three different braking systems. Which three?
2How does the emergency brake system on an air-braked vehicle work, according to the Louisiana CDL Manual?
3What does the air compressor do in an air brake system?
4If the air compressor has its own oil supply, what does the Louisiana CDL Manual say to do?
5With the engine at fast idle, you watch the supply gauges climb until the governor unloads the compressor and the needles stop rising. Near what reading should that happen?
6With the engine idling, you step on and off the brake pedal and watch tank pressure fall. At about what reading should the compressor start building pressure again?
7What does the Louisiana CDL Manual say about how much air the storage tanks hold?
8Why must air tanks be drained?
9If your vehicle's air tanks have manual drain valves, how often does the Louisiana CDL Manual say you must drain them?
10How is a manually operated air tank drain valve opened?
About the LA CDL Air Brakes Exam
The Louisiana CDL Air Brakes Knowledge Test is required if your commercial vehicle has air brakes, including air-over-hydraulic brakes. Louisiana OMV gives it on its automated testing system in English, French, or Spanish, and it covers Section 5 of the Louisiana CDL Manual; scoring below 80% adds an air brake restriction. You must also complete the three-part air brake check during the skills test. This independent English-language practice bank helps you study for the knowledge test only; it does not replace the hands-on air brake check.
Exam sponsor: Louisiana Office of Motor Vehicles (OMV), Department of Public Safety and Corrections. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.
Assessment
Computer-based Air Brakes knowledge test on OMV's automated system, covering Section 5 of the Louisiana CDL Manual, plus a three-part in-cab air brake check during the skills test in an air-braked vehicle. A low score or a skills test without air brakes adds an air brake restriction.
Time Limit
Not published by Louisiana OMV
Passing Score
80% or higher on the air brake component
Exam / Certification Fees
$15 CDL application fee; no separate air brake endorsement fee
Exam sponsor websiteFees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.
Official sources
- Louisiana Commercial Driver's License Manual (2005 CDL Testing System, July 2017 version)
- Louisiana OMV Driver Manuals
- OMV Policy 10.00: Knowledge Examinations for All Classes
- OMV Policy 1.01: Commercial Learner's Permit
- La. R.S. 32:408: Examination of applicants; classes of licenses
- Louisiana OMV FAQs (CDL fees)
Our practice resources: topics covered
We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.
Air Brake System Parts
Compressor and governor (cut-out about 125 psi, cut-in about 100 psi), tanks and drains, alcohol evaporators, the 150-psi safety valve, foundation brakes, gauges, low air warnings, spring brakes, parking controls, and ABS.
Dual Air Brake Systems
Primary and secondary systems, building at least 100 psi in both before driving, and what happens when one system loses pressure.
Inspecting Air Brake Systems
Compressor belts, slack adjusters and automatic adjusters, drums and linings, governor checks, static and applied leak limits, low air warning and spring brake tests, buildup rates, and the three-part skills-test air brake check.
Using Air Brakes
Normal and emergency stops, ABS braking, controlled and stab braking, brake lag and stopping distance, brake fade, snub braking on downgrades, low air pressure, and parking brakes.
Restrictions and Louisiana Testing Rules
When the air brakes test is required, restrictions L and Z, the 80% standard in R.S. 32:408, and how to remove an air brake restriction.
Preparing for the LA CDL Air Brakes Exam
What You Need to Know
- Passing score: 80% or higher on the air brake component
- Assessment: Computer-based Air Brakes knowledge test on OMV's automated system, covering Section 5 of the Louisiana CDL Manual, plus a three-part in-cab air brake check during the skills test in an air-braked vehicle. A low score or a skills test without air brakes adds an air brake restriction.
- Time limit: Not published by Louisiana OMV
- Exam / certification fees: $15 CDL application fee; no separate air brake endorsement fee Official sources
Using Our Practice Resources
- Work through all 220 available questions
- Review every answer and explanation
- Track weak areas and revisit them
- Use our AI tutor for tough concepts
LA CDL Air Brakes: Suggested Study Strategy
Frequently Asked Questions
What is restriction L on a Louisiana CDL?
Restriction L means no CMV equipped with any type of air brakes. It is added if you do not take or fail the air brake knowledge test, or take the skills test in a vehicle without air brakes. Testing in an air-over-hydraulic vehicle adds restriction Z instead.
How many questions are on the Louisiana Air Brakes test?
Louisiana OMV does not publish an item count or time limit for the Air Brakes knowledge test. La. R.S. 32:408 requires 80% or higher on the air brake component, and the test covers Section 5 of the manual.
When must the low air pressure warning come on?
Section 5 of the Louisiana CDL Manual says a visible warning must come on before tank pressure falls below 60 psi (or half the governor cut-out pressure on older vehicles). The manual notes that large buses commonly warn at 80 to 85 psi.
What are the air leakage limits?
With the brakes released, a single vehicle should lose less than 2 psi per minute and a combination less than 3 psi. With the foot brake fully applied for one minute, the limits are 3 psi for a single vehicle and 4 psi for a combination.
At what pressure do the spring brakes come on?
The manual says tractor and straight truck spring brakes come fully on when pressure drops to 20 to 45 psi, typically 20 to 30 psi. Stop as soon as the low air warning comes on, while you can still control the brakes.
How do I remove an air brake restriction in Louisiana?
OMV Policy 10.00 says you must pass the air brakes knowledge exam, obtain a permit, and pass a skills test in a commercial motor vehicle equipped with air brakes.