Knowledge Test Class A #1
Class A Driving Test | District Of Columbia 2026 #1 Page 5 of 7
Train for FREE online with our District Of Columbia class A 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 A permit in 2026, 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 A requirements may vary from state to state.
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29 . What should happen if the air pressure in the braking system's air tanks falls below 60 psi?
The steering wheel will lock up.
On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.
30 . 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.
31 . When approaching a downgrade, how can you reduce the amount of braking that will be needed?
Turn off the engine.
Always shift to a lower gear before starting down a hill. Doing this will help your vehicle maintain a safe speed without you needing to use the brakes too much.
32 . After a tire has been changed, the driver should stop after a short distance to:
See if rocks have gotten into the tread.
After a tire has been changed, you should stop a short while later to re-check the tightness of the lug nuts.
33 . A dual air brake system:
Has two separate air brake systems, but uses a single set of controls.
A dual air brake system has two separate air brake systems that use a single set of brake controls. One system typically operates the regular brakes on the rear axle or axles. The other system operates the regular brakes on the front axle.
34 . An item that is 40 feet long placed on a flatbed trailer should be secured by at least ____ tie-down(s).
Four
Cargo on a flatbed trailer should be secured by at least one tie-down for every 10 feet of the cargo's length. Cargo should be secured by a minimum of two tie-downs, regardless of size.
35 . During a static leakage test, the maximum leakage rate for a single vehicle with air brakes is ____ in one minute.
4 psi
