Instructions

Air Brakes

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice.. Read More

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the South Dakota Commercial Driver License Manual. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.

Number of Question 25

Passing Score 20

1. Most heavy-duty vehicles use ____ air brake systems.

Single

Dual

Triple

Quad

The majority of heavy-duty vehicles are equipped with dual air brake systems.

2. 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.

3. Braking mechanisms are located ____ a brake drum.

Outside

Inside

Next to

On top of

Drum brakes are attached to the wheels and located on the axles of a vehicle. The braking mechanisms that cause the vehicle to stop can be found inside of a drum brake.

4. Truck tractors with air brakes that were built on or after March 1, 1997 are equipped with:

An extra set of brakes.

Voice-activated brakes.

Cruise control.

Anti-Lock Braking Systems (ABS).

Truck tractors with air brakes that were manufactured on or after March 1, 1997 are required to be equipped with Anti-Lock Braking Systems (ABS). ABS is required in any other type of vehicle with air brakes that was manufactured on or after March 1, 1998.

5. Failing to drain air tanks could result in:

Water accumulations freezing and causing brake failure.

Squishy brakes.

Too much air collecting in the tanks.

In an air brake system, the air tanks must be periodically drained to remove accumulations of water and compressor oil. If water is not removed, it could freeze in cold weather and cause brake failure.