Air Brakes Endorsement Test | District Of Columbia 2026 #2

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 2026, 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.

Number of Question 25

Passing Score 20

Number of Tests 20

1 . Air tank drains:

Allow rain water to enter air tanks.

Are used to drain water and oil from air tanks.

Should never be opened.

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.

2 . When only the tractor is equipped with an Anti-Lock Braking System (ABS):

There is a decreased risk of jackknifing.

There is an increased risk of jackknifing.

The brakes will not work as effectively as they would without ABS.

The brakes will become more sensitive.

If a tractor is equipped with an Anti-Lock Braking System (ABS) but the trailer is not, the risk of jackknifing will be reduced and the driver should still be able to maintain steering control. If only the trailer is equipped with ABS, it is less likely that the trailer will swing out to one side.

3 . How is the parking brake released?

By tapping on the brake pedal three times

By pushing in the brake control knob

By engaging the accelerator

By tapping the accelerator twice

In newer vehicles with air brakes, the parking brakes are controlled by a diamond-shaped yellow knob. Pull the knob out to activate the parking brakes and push it in to release them.

4 . Service brakes should:

Be tested once a month.

Only be tested by a trained mechanic.

Be tested before every trip.

Before driving, you should always verify that your service brakes are in good working order. Testing the brakes before a trip allows you to locate any problems before you need to brake while on the road.

5 . If a vehicle has air brakes, the air compressor drive belt should be checked before each drive. In what condition should the belt be?

Loose

Tight

Cracked

Bumpy

When inspecting a vehicle with air brakes that has a belt-driven air compressor, you should check the condition and tightness of the belt. It should be in good condition.

6 . To make a stop in a vehicle using air brakes, the driver should:

Press down the brake pedal.

Lift the brake pedal toward them.

Push in the brake knob.

Pull out the brake knob.

To make a normal stop in an air-braked vehicle, push the brake pedal down and control the pressure so that the vehicle comes to a smooth, safe stop.

Study tip:

Reduce your study time from hours to minutes with a DMV exam “Cheat Sheet”

99.2% of people who use the cheat sheet pass the FIRST TIME

Click Here
Full Cheat Sheet

99.2%

99.2% of people who use the cheat sheet pass the FIRST TIME

2026 District Of Columbia | Frequently Asked Questions

To acquire a CDL Passenger endorsement in the District of Columbia, you must first hold a valid CDL. You then need to pass a written passenger endorsement test and a skills test in a vehicle similar to the one you'll be driving. The test covers topics like vehicle inspection, loading/unloading passengers, and emergency procedures.

To obtain a CDL Passenger license in the District of Columbia, an applicant must possess a valid CDL, pass the Passenger Transport written test, complete a Federal Motor Carrier Safety Administration medical examination, and successfully pass a skills test in the type of vehicle similar to the one they will be driving. The applicant must also be at least 21 years old.

Yes, specific training is necessary to earn a CDL Passenger endorsement in the District of Columbia. You must pass a written passenger endorsement test and a skills test in a vehicle similar to the one you'll be driving. While not mandatory, practical experience driving similar vehicles can be beneficial for passing the skills test.

Yes, to secure a CDL Passenger endorsement in the District of Columbia, you are required to pass a written passenger endorsement test. This test covers topics such as vehicle inspection, loading/unloading passengers, and emergency procedures. It is designed to ensure you have the necessary knowledge to safely operate a passenger vehicle.

During the CDL Passenger endorsement skills test, you'll need to demonstrate your ability to safely operate a passenger vehicle. This includes pre-trip vehicle inspection, proper use of mirrors and signals, safe lane changes and turns, proper loading/unloading procedures, and emergency protocol. Your ability to control and maneuver the vehicle in various traffic situations will also be assessed.

No, it is illegal to transport passengers without holding a valid CDL Passenger endorsement in the District of Columbia. A CDL Passenger endorsement is required to operate a commercial vehicle that is designed to transport 16 or more passengers, including the driver. Failure to have the proper endorsement can result in fines and penalties.

Yes, you can add the CDL Passenger endorsement to your existing commercial driver's license. You don't need a new application. However, you must pass the Passenger endorsement written test and a skills test in a passenger vehicle. Remember to bring your current CDL to the DMV when you go for your tests.

Yes, there are specific restrictions for drivers with a CDL Passenger endorsement. For instance, you cannot transport more passengers than your vehicle is designed to carry. Additionally, you are subject to stricter blood alcohol content (BAC) limits and may be disqualified for serious traffic violations or multiple minor violations.

Yes, there are age-related prerequisites and limitations for acquiring the CDL Passenger endorsement in the District of Columbia. To obtain the endorsement, you must be at least 18 years old. However, if you plan to transport passengers across state lines or operate a vehicle with hazardous materials, you must be at least 21 years old. Additionally, certain medical and physical requirements must be met to qualify for the endorsement.

With a CDL Passenger endorsement, you'll be eligible to operate vehicles such as buses, shuttles, or any other vehicle designed to transport 16 or more passengers, including the driver. This includes school buses if you also have a School Bus endorsement. It's important to note that the specific vehicle must match the class of your CDL.