Save Time and Get a Pass Guarantee! LIMITED-TIME OFFER: Get CDL PREMIUM Now and SAVE $64! Upgrade To Premium


View instructions
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 Missouri CDL knowledge test. The MO 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 Missouri CDL Manual. Take this MO CDL practice test now to prepare for the actual air brakes test!
1. To prevent rollover, you should:
keep the cargo as close to the ground as possible.
go slowly around turns.
All of the above.
2. When you apply the brakes, the brake shoes and linings are pushed against:
the S-cam.
the supply pressure gauge.
None of the above.
3. When the spring brakes are on, you should push the brake pedal down:
Only when driving uphill.
Only when driving downhill.
4. How should you apply the brakes when going down a steep downgrade?
Apply the brakes whenever you reach your safe speed, until your speed has been reduced to 5 mph below your safe speed.
Apply the brakes when you reach the bottom of the downgrade.
Apply the brakes as hard as you can without locking the wheels.
5. If you are being tailgated, you should:
move to the left lane.
speed up.
increase your following distance.
6. In combination vehicles with air brakes, the trailer air supply control should pop out when the air pressure falls within the range of:
10 to 20 psi
100 to 120 psi
20 to 45 psi
7. Before driving a vehicle with a dual air brake system, you should allow time for the air compressor to build up a minimum of ____ pressure in both the primary and secondary systems.
100 psi
50 psi
150 psi
8. When going down a steep downgrade, you should:
use a low gear, and a proper braking technique.
avoid braking and rely on engine braking.
use the parking brake.
9. You hear a loud "bang" which sounds like a tire blowout. You should:
check the tires at the next stop.
keep driving as normal.
assume you have a tire failure.
10. When the spring brakes are on, you should:
press the accelerator.
not push the brake pedal down.
pump the brakes.
Page 1 of 3
Next page  
Rate This Free Test
4.9 out of 5
based on 335 votes

MO Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
Number of questions: 25
Correct answers to pass:20
Passing score:80%
Share This Online CDL Test