Air Brakes #1
Air Brakes Endorsement Test | West Virginia 2024 #1 Page 4 of 4
Train for FREE online with our West Virginia 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 WV 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.
25
20
20
19 . Applying the brake pedal causes air pressure to activate an electric switch and:
Turn off the low pressure warning light.
In a vehicle with air brakes, the brake lights are activated when the brake pedal is pushed and air pressure moves an electric switch. With the application of air pressure, the switch will then turn on the brake lights.
20 . What is brake lag?
How faded the brakes are
Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work. On vehicles with hydraulic brakes, the brakes work instantly when the pedal is pressed.
21 . If the air pressure warning light comes on, you should:
Safely exit the roadway and stop.
If the low air pressure warning signals activate, it is essential that you bring the vehicle to a safe stop while you are still able to control the brakes.
22 . Why do you need to drain air tanks regularly?
To remove bad air from the tanks
Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.
23 . When you need to stop in an emergency, you should:
Expect your vehicle to slow down more quickly than usual.
If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle traveling in a straight line while still allowing you to turn, if necessary.
24 . The emergency brake system uses:
Only parts unique to the emergency brake system.
In an air brake system, there are three different braking systems: a service brake system, a parking brake system, and an emergency brake system. The emergency brake system uses parts of both the parking and service brake systems.
25 . What does ABS do?
Prevent the brakes from being used if downshifting would be more effective
