Career upgrade: Learn practical AI skills for better jobs and higher pay.
Level up
PracticeVideosBlogFlashcardsEspañol
All Practice Exams

200+ Free Michigan CDL Air Brakes Practice Questions

Pass your Michigan CDL Air Brakes Knowledge Test exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
200+ Questions
100% Free
1 / 200
Question 1
Score: 0/0

On the Michigan CDL Air Brakes test, what are glad hands?

A
B
C
D
to track
Same family resources

Explore More CDL Air Brakes Knowledge Test

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

Alabama CDL Air Brakes Knowledge Test

Practice Questions

Arkansas CDL Air Brakes Knowledge Test

Practice Questions

California CDL Air Brakes Knowledge Test

Practice Questions

Colorado CDL Air Brakes Knowledge Test

Practice Questions

Florida CDL Air Brakes Knowledge Test

Practice Questions

Georgia CDL Air Brakes Knowledge Test

Practice Questions
2026 Statistics

Key Facts: Michigan CDL Air Brakes Exam

25

Michigan Air brakes knowledge-test questions

Michigan SOS Applying for a CDL

80%

Minimum CDL knowledge-test passing score

Michigan SOS and 49 CFR 383.135

7

Required federal air-brake knowledge areas

49 CFR 383.111(b)

$25

First-time standard Michigan CDL fee

Michigan License and ID Costs and Fees

1 day

Michigan CDL knowledge-test retake wait after a failed attempt

Michigan SOS Applying for a CDL

20-45 psi

Typical manufacturer range for spring brake pop-out/application

Michigan CDL Manual Section 5

85 to 100 psi

Dual-system buildup range that should be reached within 45 seconds at operating rpm

Michigan CDL Manual Section 5

Use Michigan CDL Manual Section 5 as the primary source for the Michigan CDL Air Brakes test. Michigan SOS lists Air brakes as a 25-question knowledge test and requires at least 80% to pass each CDL knowledge test. Michigan also warns that failing the air-brake test or failing to provide a properly equipped air-brake vehicle for the skills test results in an air-brake restriction. Key numbers include about 100 psi governor cut-in, about 125 psi cut-out, 150 psi safety valve, low-air warning before 55 psi, spring brakes at 20-45 psi, 85-to-100 psi buildup within 45 seconds in dual systems, and leak-rate limits of 2/3 psi released and 3/4 psi applied for single/combination vehicles.

Sample Michigan CDL Air Brakes Practice Questions

Try these sample questions to test your Michigan CDL Air Brakes exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 200+ question experience with AI tutoring.

1For Michigan CDL air-brake testing, what component compresses air for the air brake system?
A.The air dryer
B.The air compressor
C.The brake chamber
D.The slack adjuster
Explanation: The air compressor pumps air into the air storage tanks. It is driven by the engine, either through belts or directly. The air dryer removes moisture from the compressed air, the brake chamber converts air pressure into mechanical force at each wheel, and the slack adjuster transfers that force to the S-cam. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
2Under Michigan CDL Manual Section 5, what is the typical air compressor governor cut-out pressure range?
A.60 to 80 psi
B.100 to 125 psi
C.125 to 140 psi
D.150 to 175 psi
Explanation: The governor cuts out the compressor (stops pumping) at about 125 to 140 psi. It cuts back in (resumes pumping) at about 100 to 125 psi. This pressure range keeps the system safely above the low-pressure warning threshold of 60 psi while preventing over-pressurization. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
3On the Michigan CDL Air Brakes test, at what pressure does the air compressor governor typically cut IN to resume pumping?
A.60 to 80 psi
B.100 to 125 psi
C.125 to 140 psi
D.145 to 150 psi
Explanation: The governor typically cuts in at 100 to 125 psi, signaling the compressor to resume pumping. It cuts out at 125 to 140 psi when system pressure is sufficient. Together these limits maintain a safe operating range well above the 60 psi low-pressure warning. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
4For an Michigan CDL air-brake vehicle, what is the purpose of the air dryer in the brake system?
A.To cool the air before storage
B.To remove moisture and oil before air reaches the tanks
C.To increase compressed air pressure
D.To warn the driver of low pressure
Explanation: The air dryer uses a desiccant cartridge to remove water vapor and oil from compressed air before it enters the storage tanks. Removing moisture prevents corrosion, contamination of brake components, and dangerous freezing of air lines in cold weather. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
5For Michigan CDL air-brake testing, what is the function of the wet tank (supply or service reservoir)?
A.It cools brake fluid
B.It is the first storage tank where moisture collects before air moves to the other tanks
C.It supplies air only to the trailer
D.It activates the parking brakes
Explanation: The wet tank is the first storage reservoir downstream of the compressor. Most moisture and oil that gets past the air dryer settles there before clean air moves on to the primary and secondary tanks. Drivers must drain the wet tank daily to prevent contamination of the rest of the system. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
6Under Michigan CDL Manual Section 5, at what pressure does the safety valve in the supply tank typically open to release excess air?
A.100 psi
B.125 psi
C.150 psi
D.200 psi
Explanation: The safety valve, installed in the supply (wet) tank, is set to open at about 150 psi. It is a backup that protects the system if the governor fails to cut out the compressor. If the valve releases, the compressor or governor needs immediate repair. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
7On the Michigan CDL Air Brakes test, what is the role of the foot valve (also called the treadle or service brake valve)?
A.It locks the parking brake
B.It supplies air to the brake chambers in proportion to how hard the driver presses the pedal
C.It drains water from the tanks
D.It controls the trailer air supply
Explanation: The foot valve (treadle valve) meters air to the brake chambers in proportion to how far the driver depresses the brake pedal. Pressing harder sends more air, applying more braking force. Releasing the pedal exhausts air from the chambers, allowing the springs and slack adjusters to release the brakes. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
8For an Michigan CDL air-brake vehicle, what does the brake chamber do?
A.Stores compressed air for emergencies
B.Converts air pressure into mechanical force through a pushrod
C.Cools brake drums during use
D.Acts as a backup for the parking brake
Explanation: A brake chamber is a sealed housing with a diaphragm or piston. When air pressure enters, the diaphragm pushes a pushrod outward. The pushrod rotates the slack adjuster and S-cam, which forces the brake shoes against the drum to apply braking force. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
9For Michigan CDL air-brake testing, what is the role of the slack adjuster on an S-cam brake?
A.It cushions the impact of hard braking
B.It transfers force from the pushrod to the S-cam and can be adjusted to compensate for lining wear
C.It bleeds water from the system
D.It limits maximum air pressure
Explanation: The slack adjuster is a lever that connects the brake chamber pushrod to the S-cam. As the pushrod extends, the slack adjuster rotates the S-cam, which pushes the brake shoes against the drum. It can be adjusted to maintain proper pushrod travel as brake linings wear. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.
10Under Michigan CDL Manual Section 5, what does the S-cam do in an S-cam drum brake?
A.It releases air from the lines
B.It rotates between the brake shoes, forcing them outward against the drum
C.It cools the brake drum
D.It activates the low-pressure warning
Explanation: The S-cam is an S-shaped piece of steel between the two brake shoes. When the slack adjuster rotates it, the wide part of the S forces the shoes outward against the drum, creating friction and slowing the wheel. When air pressure is released, return springs pull the shoes back and rotate the S-cam to its original position. This Michigan version is aligned to Michigan CDL Manual Section 5 and FMCSA CDL air-brake standards.

About the Michigan CDL Air Brakes Exam

The Michigan CDL Air Brakes Knowledge Test is required for Michigan CDL or CLP applicants who will operate commercial motor vehicles equipped with air brakes without an air-brake restriction. Michigan SOS lists the air-brakes written test as 25 questions, requires at least 80 percent on each CDL knowledge test, and administers knowledge testing at computer testing stations. The official study content is the Michigan Commercial Driver License Manual, especially Section 5, together with FMCSA CDL standards in 49 CFR Part 383. Study areas include the compressor and governor, air tanks and drains, contaminated air, alcohol evaporators, low-air warnings, dual air systems, spring brakes, parking brakes, ABS, brake lag, emergency braking, brake fade, downgrade control, slack adjusters, foundation brakes, air-leak and buildup tests, inspection procedures, and older front brake limiting valves.

Assessment

Separate 25-question Michigan CDL air-brake knowledge test based on Michigan CDL Manual Section 5 and the seven FMCSA air-brake knowledge areas in 49 CFR 383.111(b).

Time Limit

Computer-based written testing at a Michigan Secretary of State office; no separate public time limit found in official Michigan SOS sources

Passing Score

80% minimum on each CDL knowledge test

Exam Fee

$25 first-time standard CDL; $5 each standard group designation/endorsement; $18 standard CDL replace/correct; third-party skills-test fees vary (Michigan Department of State, Secretary of State (SOS))

Michigan CDL Air Brakes Exam Content Outline

25%

Air Brake System Parts

Compressor, governor, storage tanks, drains, alcohol evaporator, safety valve, foot valve, foundation brakes, gauges, stop light switch, ABS, and front brake limiting valve.

15%

Dual Air Systems and Warnings

Primary and secondary systems, pressure gauges, minimum operating pressure, low-air warning devices, wig-wag operation, spring brakes, and low-pressure response.

30%

Inspection and Air Tests

Compressor belt, slack adjuster travel, automatic slack adjuster cautions, drums and linings, hoses, governor checks, leak tests, warning test, spring-brake pop-out, buildup, parking brake, and service brake checks.

20%

Using Air Brakes

Normal stops, controlled and stab braking, ABS use, brake lag, stopping distance, brake fade, downhill braking technique, low-air emergencies, wet brakes, and parking brake exceptions.

10%

Michigan and FMCSA Rules

Michigan SOS CDL testing logistics, the 25-question air-brakes test, 80% passing standard, one-day retest wait, L/Z restriction context, and 49 CFR Part 383 required knowledge.

How to Pass the Michigan CDL Air Brakes Exam

What You Need to Know

  • Passing score: 80% minimum on each CDL knowledge test
  • Assessment: Separate 25-question Michigan CDL air-brake knowledge test based on Michigan CDL Manual Section 5 and the seven FMCSA air-brake knowledge areas in 49 CFR 383.111(b).
  • Time limit: Computer-based written testing at a Michigan Secretary of State office; no separate public time limit found in official Michigan SOS sources
  • Exam fee: $25 first-time standard CDL; $5 each standard group designation/endorsement; $18 standard CDL replace/correct; third-party skills-test fees vary

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

Michigan CDL Air Brakes Study Tips from Top Performers

1Memorize the pressure numbers first: about 100 psi cut-in, about 125 psi cut-out, 150 psi safety valve, warning before 55 psi, spring brakes at 20-45 psi, and 85-to-100 psi buildup within 45 seconds in dual systems.
2Practice the air-brake check as a sequence: governor, leak rates, low-pressure warning, spring-brake pop-out, buildup, parking brake, and service brake.
3Separate service, parking, and emergency brake functions; many missed questions confuse foot-valve braking with spring parking brakes.
4Do not skip legacy topics. Michigan Section 5 still covers front brake limiting valves and wig-wag warnings even though they are older equipment.
5Review ABS carefully: it helps prevent wheel lockup and maintain control, but it does not necessarily shorten stopping distance or increase normal braking power.

Frequently Asked Questions

Who administers the Michigan CDL Air Brakes Knowledge Test?

Michigan Secretary of State offices administer Michigan CDL written knowledge testing at computer testing stations. Skills tests are administered by state-approved Driver Testing Businesses.

How many questions are on the Michigan air-brakes test?

Michigan SOS lists the Air brakes written knowledge test as 25 questions.

What score do I need to pass?

Michigan SOS states that a minimum score of 80 percent is required to pass each CDL knowledge test. Federal CDL rules in 49 CFR 383.135 use the same minimum.

What happens if I do not pass the air-brake test?

Michigan SOS states that if you do not pass the air-brake test or fail to provide a properly equipped air-brake vehicle for the skills test, you will be restricted from operating vehicles with air brakes.

What should I study?

Study Michigan CDL Manual Section 5, including system parts, dual air brakes, inspections, leak and buildup tests, low-air warnings, spring brakes, ABS, brake lag, emergency braking, brake fade, downgrade braking, alcohol evaporators, and front brake limiting valves.