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.
2025 District Of Columbia | Frequently Asked Questions
In the District of Columbia, you can acquire a CDL Tank endorsement by first holding a valid CDL. You need to pass the Tank Vehicle written test, which covers topics like inspecting tank vehicles, driving tank vehicles, and safe driving rules. After passing the test, you pay the required fee to add the endorsement to your CDL.
To obtain a CDL Tank license in the District of Columbia, you must first have a valid Commercial Driver's License (CDL). Then, you must take and pass the Tank Vehicle written test, which covers topics such as inspecting and driving tank vehicles, and safe driving rules. After passing, pay the necessary fee to add the endorsement to your CDL.
While the District of Columbia doesn't explicitly require specific training or experience for a CDL Tank endorsement, it's highly recommended. Understanding how to safely operate tank vehicles is crucial. Passing the Tank Vehicle Endorsement Knowledge Test requires knowledge of tank vehicle operations, so training or experience can be beneficial in passing the test.
Yes, for a CDL Tank endorsement in the District of Columbia, you must pass the Tank Vehicle written test. This exam covers important topics like inspecting tank vehicles, driving tank vehicles, and safe driving rules. Passing this test is crucial to demonstrate your knowledge and understanding of operating tank vehicles safely.
The written test for the CDL Tank endorsement in the District of Columbia covers a variety of subjects. These include inspecting tank vehicles, driving tank vehicles, and understanding the unique handling characteristics of tank vehicles. It also tests knowledge on safe driving rules and regulations specific to tank vehicles.
During the CDL Tank endorsement assessment, several skills and maneuvers are assessed. These include inspecting the tank vehicle for safety, demonstrating proper loading and unloading procedures, controlling the vehicle's speed and position, performing backing maneuvers, and executing turns and lane changes safely. Additionally, candidates are evaluated on their ability to handle emergency situations and demonstrate knowledge of hazardous materials regulations.
Drivers with a CDL Tank endorsement in the District of Columbia must comply with specific federal and state regulations. These include restrictions on maximum driving hours to prevent fatigue, mandatory rest periods, and stringent vehicle inspection requirements. Additionally, they must follow rules related to the transportation of hazardous materials if their tank vehicle is used for such purposes.
No, a valid CDL Tank endorsement is required to legally transport liquid or gas materials in the District of Columbia. This endorsement is necessary due to the unique handling and safety requirements associated with transporting such materials. Violating this requirement can result in significant penalties, including fines and suspension of driving privileges.
You can add the CDL Tank endorsement to your existing Commercial Driver's License (CDL) without needing a fresh application. However, you will need to pass a written knowledge test specific to tank vehicles and pay the necessary endorsement fee. Remember, additional endorsements may require further testing.
Yes, to handle hazardous materials with a CDL Tank endorsement, you must also obtain a Hazardous Materials (HazMat) endorsement. This requires passing an additional written test and undergoing a federal background check. Also, adherence to specific regulations regarding the transportation and handling of such materials is mandatory.