Air Brakes #1
Air Brakes Endorsement Test | District Of Columbia 2024 #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 2024, 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.
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2024 District Of Columbia | Frequently Asked Questions
A CDL Class B license in the District of Columbia authorizes the holder to operate vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more, or any such vehicle towing another not in excess of 10,000 pounds. This includes buses, dump trucks, delivery trucks, and other medium to heavy commercial vehicles.
A Class B CDL license in the District of Columbia allows the holder to operate single vehicles with a Gross Vehicle Weight Rating of 26,001 pounds or more, or any such vehicle towing another not exceeding 10,000 pounds. This includes buses, dump trucks, segmented buses, delivery trucks, and utility trucks.
To acquire a Class B CDL license in District of Columbia, you must be at least 21 years old, possess a valid DC driver's license, pass a vision test, and complete a commercial driver's license application. You'll also need to pass a general knowledge test and a skills test, which includes a pre-trip vehicle inspection, a basic control skills test, and an on-road driving test.
In the District of Columbia, you must be at least 21 years old to qualify for a Class B CDL license. This is the age requirement set by the Federal Motor Carrier Safety Administration for interstate travel. However, some states may allow individuals aged 18 and above to drive within that state's borders.
While not always necessary, specific endorsements can expand the types of vehicles you can operate with a Class B CDL license in the District of Columbia. These include passenger vehicles (P), school buses (S), and tank vehicles (N). Each endorsement requires additional testing.
The Class B CDL skills assessment in the District of Columbia encompasses three main parts: a pre-trip vehicle inspection, a basic vehicle control test, and an on-road driving test. These tests assess your ability to inspect your vehicle, control its basic functions, and drive it safely on the road.
Yes, Class B CDL license holders in the District of Columbia are limited to operating vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more. They can also tow trailers that weigh less than 10,000 pounds. They cannot operate Class A vehicles without the appropriate endorsement.
Yes, in the District of Columbia, the written Class B CDL test is available in several languages other than English. However, federal regulations require 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, in the District of Columbia, test accommodations for people with disabilities are available for the Class B CDL written exam. You can request accommodations through the DC Department of Motor Vehicles. However, you need to provide supporting documentation of your disability to qualify for these accommodations.
Yes, if you don't pass the Class B CDL written test in the District of Columbia, you can retake it. However, you must wait at least three business days before retesting. If you fail six times within a year, you'll have to wait one year from the date of the last test before retaking it.
