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The air brakes endorsement applies to applicants who wish to drive a vehicle with air brakes in Class A, B, or C CDL. To drive a vehicle with air brakes, you must pass the air brake component of the Ohio CDL knowledge test. The OH CDL air brakes test consists of 25 questions, and you'll need at least 20 correct answers to pass (80%). The test covers the information found in the air brakes section of the Ohio CDL Manual. Take this OH CDL practice test now to prepare for the actual air brakes test!
1. Why should you check your mirrors regularly to know where other vehicles are around you?
To know whether you can make a quick lane change in an emergency.
To move out of their way if they want to get past.
To flash the brake lights if you are being tailgated.
2. If your truck catches fire, the first thing you should do is to:
get the vehicle off the road and park near other vehicles.
pull off the road and park in an open area.
pull into a service station and call for help.
3. The total stopping distance for vehicles with air brake systems is made up of __ different factors.
4. You should NOT use the parking brakes if:
the brakes are cold.
the brakes are very hot.
the brakes are too dry.
5. If you get stuck on railroad tracks, you should:
have a helper push your vehicle.
get out of the vehicle and away from the tracks.
stay in the vehicle and call for help.
6. With the air pressure built up to governor cutoff, the maximum leakage rates per minute are ___ psi for single vehicles and ___ psi for a combination of 2 vehicles.
5; 6
3; 2
3; 4
7. It is not safe to drive a vehicle that has brake drums with cracks that are longer than ___ the width of the friction area.
8. Stepping on and off the brake pedal several times:
reduces the air pressure in the tanks.
may cause air leaks.
may result in dangerously thin linings.
9. The wig wag is:
a low air pressure warning system.
a noise reduction mechanism.
a type of rollover.
10. Supply pressure gauges tell you:
how much air pressure you are applying to the brakes.
when the air pressure in the tanks falls below 60 psi.
how much pressure is in the air tanks.
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OH CDL Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
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