FREE Double Triple Test Online | District Of Columbia 2024
Train for FREE with our District Of Columbia CDL double triple practice test online. 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 CDL double triple license in 2021, 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 DMV requirements may vary from state to state.
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1 . Belts in the engine compartment should be:
Easy to slide off.
When inspecting your vehicle's engine, check the belts for tightness and excessive wear. The amount of "give" that is safe for each belt in a given engine will vary, so learn what is appropriate for your vehicle.
2 . When coupling a double or triple, which trailer should be attached last?
It doesn’t matter.
When coupling a double or triple combination, the rearmost trailer should be the final trailer attached.
3 . 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.
4 . The ____ tells a driver how much pressure is in the air tanks.
Drum brake
A vehicle that is equipped with air brakes must also be equipped with a supply pressure gauge. This gauge tells the driver how much air pressure is in each of the vehicle's air tanks.
5 . When it is difficult for others to see your vehicle, such as at dawn or dusk, you can help other drivers by:
Waving an arm out the window.
At times when visibility is low, you should turn your headlights on to the low beam setting. If you are having a difficult time seeing others, they are probably having a difficult time seeing you.
6 . Test the low pressure warning signal:
Before every trip.
It is essential that your low pressure warning light function properly. After allowing the system to charge, you can test the warning signal by rapidly applying and releasing the brake pedal. This will release air from the braking system and the warning signal should come on when pressure drops to a dangerous level.
7 . When passing another vehicle, you should:
Wait for the other driver to signal that it is safe to do so.
