Air Brakes #1
Air Brakes Endorsement Test | District Of Columbia 2025 #1 Page 4 of 4
Train for FREE online with our District Of Columbia CDL air brake test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a DC Class A/Class B driver license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that the requirements for CDL may vary from state to state.
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19 . When the spring brakes are activated in a vehicle with air brakes, you should never:
Open the trailer doors.
In a vehicle with air brakes, never push the brake pedal down when the spring brakes are activated. The combined force of the springs and the pressure of the air brakes could damage the brakes.
20 . Emergency brakes:
Are optional.
All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes. These brakes must be held by mechanical force.
21 . When inspecting your brakes, a slack adjuster should move ____ from where it is attached to the push rod.
No more than one inch
Check each slack adjuster after setting wheel chocks and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.
22 . Air tank drains:
Must remain open while driving.
In an air brake system, the air tanks are equipped with drains that allow water and compressor oil to be removed from the system. If allowed to build up, water and compressor oil can damage an air brake system.
23 . What should happen if the air pressure in the braking system's air tanks falls below 60 psi?
The steering wheel will lock up.
On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.
24 . What does the air compressor governor do?
Controls the temperature of the air leaving the air storage tanks.
In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.
25 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
See the exact questions that will be on the 2025 District Of Columbia DMV exam.
99.2% of people who use the cheat sheet pass the FIRST TIME
Lillian MCcranie explains how our CDL study guide was helpful in passing the exam and recommends it to everyone.
Cameron tells us how he purchased the CDL exam, and found it to be a useful tool which helped him pass the exam and find a job.
2025 District Of Columbia | Frequently Asked Questions
In the District of Columbia, a CDL Class A license allows the holder to operate any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, provided the Gross Vehicle Weight Rating (GVWR) of the vehicle(s) being towed is over 10,000 pounds. This includes tractor-trailers, truck and trailer combinations, and flatbeds.
A Class A CDL license in the District of Columbia permits the holder to operate various types of larger, heavier commercial vehicles. This includes tractor-trailers, truck and trailer combinations, tank vehicles, livestock carriers, and flatbeds. The vehicles can have a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more if the towed vehicle is over 10,000 pounds.
To obtain a Class A CDL license in the District of Columbia, you must be at least 21 years old, possess a valid non-commercial driver's license, pass a vision test, and provide proof of residency and identity. You'll also need to pass written knowledge tests, obtain a Commercial Learner's Permit (CLP), and successfully complete a skills and road test.
In the District of Columbia, you must be at least 21 years old to qualify for a Class A Commercial Driver's License (CDL). This age requirement is consistent across all states and is set by federal regulation. This allows for interstate operation of commercial vehicles. For intrastate (within the same state), the minimum age can be 18.
Specific endorsements are not required for a Class A CDL license but they can provide additional driving privileges. These include endorsements for operating vehicles like school buses, passenger vehicles, tank vehicles, and vehicles carrying hazardous materials. Each endorsement requires passing specific knowledge and skills tests.
The Class A CDL skills test in the District of Columbia consists of three parts: the vehicle inspection test, the basic control skills test, and the road test. The vehicle inspection test involves checking the vehicle's safety components, the basic control skills test assesses your ability to maneuver and control the vehicle, and the road test evaluates your on-road driving skills.
Yes, limitations can be imposed on Class A CDL license holders in the form of restrictions. These are based on the driver's abilities or the type of vehicle they tested in. For example, if a driver takes the skills test in an automatic transmission truck, they will have an 'E' restriction, limiting them to automatic transmission vehicles only.
Yes, it is possible to take the written Class A CDL test in languages other than English in the District of Columbia. However, the Federal Motor Carrier Safety Administration requires all CDL holders to read and speak English sufficiently to converse with the general public, understand highway traffic signs and signals, respond to official inquiries and make entries on reports and records.
Yes, you can request accommodations for the Class A CDL written test in the District of Columbia due to disability. The DMV is committed to providing accessible services and accommodations to individuals with disabilities. You should contact the DMV directly in advance of your test to discuss your needs and the potential accommodations available.
If you don't pass the Class A CDL written test in the District of Columbia, you are allowed to retake it. However, you must wait three days before retaking the test. If you fail the test three times, you must wait 90 days before taking it again. There's also a retesting fee that applies each time.
