Knowledge Test Class B #1
Class B Driving Test | District Of Columbia 2025 #1 Page 4 of 7
Train for FREE online with our District Of Columbia class B license 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 CDL class B permit in 2025, 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 CDL class B requirements may vary from state to state.
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22 . Which of the following is not a problem?
Exhaust system parts that are not leaking
When inspecting an exhaust system, you should verify that parts of the system are not loose, broken, or missing. The system's parts must be properly mounted and should not be rubbing against moving parts of the vehicle.
23 . In a vehicle with dual air brakes, what happens if one system is low on pressure?
The low system will use an auxiliary system to fill the tank.
In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.
24 . When stopping a manual transmission vehicle, what should you do when the engine is close to idle?
Shut off the vehicle.
When stopping a vehicle with a manual transmission, you should push in the clutch when the engine is close to idle.
25 . Dry bulk tanks:
Cannot be driven on interstates.
Dry bulk tanks require special care when being driven because they have high centers of gravity. Drivers should also be careful because the materials being carried can easily shift in transit, causing a change in the vehicle's handling.
26 . When doing an inspection, ensure that the brake pads are:
Free of oil or grease.
When inspecting a vehicle's brakes, you should make sure the shoes and pads do not have oil, grease, or brake fluid on them.
27 . If your brakes fail on a downgrade, your best hope to stop is:
Hitting a slower vehicle in front of you.
If your brakes fail on a downgrade, your best option is to use an escape ramp. If no escape ramp is available, it is a good idea to look for a different escape route, such as a side road or open field.
28 . Air tank drains:
Must remain open during transit.
