In Partnership with William K. Kohrs Memorial Library

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 Montana CDL knowledge test. The MT 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 Montana CDL Manual. Take this MT CDL practice test now to prepare for the actual air brakes test!
1. You should drain the air tanks completely. If water and oil collect in the air tanks:
your brakes could fail.
your brakes could heat up.
your brakes could become hard to press.
None of the above.
2. The safety relief valve is usually set to open at ____ psi.
3. If the low air pressure warning light comes on, you should:
call for help.
continue to drive normally.
set the parking brake.
stop immediately.
4. The safety valve installed in the first tank the air compressor pumps air is set to open:
if there is too little pressure.
every 15 minutes.
if there is too much pressure.
at 30 psi.
5. Dual tires:
are dangerous.
should not come in contact with each other.
should always come in contact with each other.
should come in contact with each other whenever possible.
6. When going down a steep downgrade, you should:
use escape ramps whenever possible.
use the parking brake.
avoid braking and rely on engine braking.
use a low gear, and a proper braking technique.
7. Air brakes are 3 different braking systems: service brake, parking brake, and _______ brake.
air storage brake
8. The trailer hand valve should:
never be used to test the trailer brakes.
never be used for parking.
be used in driving.
All of the above.
9. The s-cam forces the brake shoes away from one another and presses them against the inside of the brake drum. It is called the s-cam because:
"S" stands for "Shoes".
it is a safe-driving brake.
it is shaped like the letter "S".
it applies a "Shock" to the brakes.
10. You are going down a steep grade. Once the vehicle is in the proper low gear, you should brake just hard enough to feel a slowdown, and then release the brakes when your speed has been reduced to ____ below your safe speed.
10 mph
20 mph
15 mph
5 mph
Page 1 of 3
Next page

MT CDL Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
Share This Online CDL Test
Rate this CDL Air Brakes Test
5 out of 5
based on 318 votes