Air Brakes #1
Air Brakes Endorsement Test | District Of Columbia 2024 #1 Page 3 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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13 . In a vehicle with dual parking control valves, once air pressure is lost and the spring brakes come on:
The air tanks will automatically refill to a safe air pressure level.
In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.
14 . When traveling down a steep downgrade, the best way to use your brakes is to:
Apply consistent pressure to the brake pedal all the way down the hill.
On a long or steep downgrade, brakes should only be used to supplement the braking effect of the engine. Apply the brakes just enough to feel a definite slowing down, then release them once you are about 5 mph below your target "safe" speed. Once your vehicle reaches its safe speed again, repeat this process.
15 . If a vehicle has air brakes, the air compressor drive belt should be checked before each drive. In what condition should the belt be?
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.
16 . To use the stab braking method, you should:
Apply the emergency brake until the vehicle starts to slow.
The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, and then the process is repeated.
17 . During a walk-around inspection, ensure there are no cracks on the brake drums that are more than ____ of the width of the friction area.
One tenth
Before beginning a trip, it is important to check the brake drums during your walk-around inspection. It is unsafe to drive if any brake drum has a crack more than one half of the width of the friction area.
18 . To make a stop in a vehicle using air brakes, the driver should:
Pull out the brake knob.
