CDL Air Brakes Test with all Correct & 100% Verified
Answers |Latest Update |Already Graded A+
To test air service brakes you should: ✔Correct Answer-Brake firmly while slowly moving forward
The driver must be able to see a low air pressure warning which comes on before pressure in the
service air tanks falls below ____ psi ✔Correct Answer-60
If your vehicle has an alcohol evaporator, every day during cold weather you should: ✔Correct
Answer-Check and fill the alcohol level
All air brakes equipped vehicles have: ✔Correct Answer-A supply pressure gauge
The most common type of foundation brake found on heavy vehicles is the: ✔Correct Answer-S-
cam drum
Modern air brakes combine three different systems. They are the service, the parking, and the ___
brakes. ✔Correct Answer-Emergency
To check the free play of manual slack adjusters of s-cam brakes, you should park on: ✔Correct
Answer-Level ground, chock the wheels and release parking breaks
Why should you drain water from compressed air tanks? ✔Correct Answer-Water can freeze in
cold weather and cause brake failure
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure
drops below____ psi ✔Correct Answer-20
With air brake vehicles, the parking brake should be used: ✔Correct Answer-Whenever you leave
the vehicle unattended
The safety valve is set automatically when pressure is ✔Correct Answer-150
Repeatedly partially increasing and pressing the brake pedal may result in: ✔Correct Answer-A loss
of air brake pressure
If your truck has dual air brake system, and one of the systems loses its pressure, what will happen?
✔Correct Answer-Either the front or rear brakes will not be fully functional
If you must make an emergency stop, you should brake so you: ✔Correct Answer-Can steer and so
your vehicle stays in a straight line
The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more
than: ✔Correct Answer-3 psi in one minute
You brakes are fading when: ✔Correct Answer-You have to push harder on a brake pedal to control
your speed on a downgrade
, Which one of these is NOT a proper time to apply the parking brakes? ✔Correct Answer-If the
brakes are very hot
The braking power of the spring brakes: ✔Correct Answer-Depends on the service brakes being in
adjustment
Your truck or bus has a dual air brake system. If a low pressure warning comes on for only one
system, what should you do? ✔Correct Answer-Bring your vehicle to a complete stop right away
and safely park. Continue only after the system is fixed
A slack adjusters free play needs to be adjusted if it is more than about _____ when you pull hard on
it. ✔Correct Answer-1 inch
The air brake lag distance at 55 mph on dry pavement adds about _____ feet ✔Correct Answer-32
An air brake system is fully charge at what psi? ✔Correct Answer-32
Emergency stab braking is: ✔Correct Answer-Press on the brake pedal as hard as you can, release
the brakes when the wheels lock, put on the brakes again when the wheels start rolling
The safety valve discharges automatically at the pressure of: ✔Correct Answer-150
The air compressor stops pumping air at what psi? ✔Correct Answer-125
If air pressure is not built up within the correct amount of time, then: ✔Correct Answer-Air
pressure may drop to low point while driving, requiring an emergency stop
Parking or emergency brakes of trucks and buses can be legally held on by _____ pressure
✔Correct Answer-spring
If air is not built up within the correct amount of time, then: ✔Correct Answer-Air pressure may
drop to a point while driving, requiring an emergency stop
The air compressor governor controls: ✔Correct Answer-When air is pumped into the air tanks
Excessive use of the service brake results in overheating which can lead to: ✔Correct Answer-
Expansion of the brake drums
When is it OK to leave your truck unattended without applying the parking brakes and choking the
wheels? ✔Correct Answer-never
The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:
✔Correct Answer-the breaking effect of the engine
The parking or emergency brake on a heavy vehicle can only be held in position by something that
cannot leak away, like: ✔Correct Answer-Spring pressure
Is it accepted that too much heat caused by using your brakes too often can also cause: ✔Correct
Answer-Brake to fade or fail
Answers |Latest Update |Already Graded A+
To test air service brakes you should: ✔Correct Answer-Brake firmly while slowly moving forward
The driver must be able to see a low air pressure warning which comes on before pressure in the
service air tanks falls below ____ psi ✔Correct Answer-60
If your vehicle has an alcohol evaporator, every day during cold weather you should: ✔Correct
Answer-Check and fill the alcohol level
All air brakes equipped vehicles have: ✔Correct Answer-A supply pressure gauge
The most common type of foundation brake found on heavy vehicles is the: ✔Correct Answer-S-
cam drum
Modern air brakes combine three different systems. They are the service, the parking, and the ___
brakes. ✔Correct Answer-Emergency
To check the free play of manual slack adjusters of s-cam brakes, you should park on: ✔Correct
Answer-Level ground, chock the wheels and release parking breaks
Why should you drain water from compressed air tanks? ✔Correct Answer-Water can freeze in
cold weather and cause brake failure
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure
drops below____ psi ✔Correct Answer-20
With air brake vehicles, the parking brake should be used: ✔Correct Answer-Whenever you leave
the vehicle unattended
The safety valve is set automatically when pressure is ✔Correct Answer-150
Repeatedly partially increasing and pressing the brake pedal may result in: ✔Correct Answer-A loss
of air brake pressure
If your truck has dual air brake system, and one of the systems loses its pressure, what will happen?
✔Correct Answer-Either the front or rear brakes will not be fully functional
If you must make an emergency stop, you should brake so you: ✔Correct Answer-Can steer and so
your vehicle stays in a straight line
The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more
than: ✔Correct Answer-3 psi in one minute
You brakes are fading when: ✔Correct Answer-You have to push harder on a brake pedal to control
your speed on a downgrade
, Which one of these is NOT a proper time to apply the parking brakes? ✔Correct Answer-If the
brakes are very hot
The braking power of the spring brakes: ✔Correct Answer-Depends on the service brakes being in
adjustment
Your truck or bus has a dual air brake system. If a low pressure warning comes on for only one
system, what should you do? ✔Correct Answer-Bring your vehicle to a complete stop right away
and safely park. Continue only after the system is fixed
A slack adjusters free play needs to be adjusted if it is more than about _____ when you pull hard on
it. ✔Correct Answer-1 inch
The air brake lag distance at 55 mph on dry pavement adds about _____ feet ✔Correct Answer-32
An air brake system is fully charge at what psi? ✔Correct Answer-32
Emergency stab braking is: ✔Correct Answer-Press on the brake pedal as hard as you can, release
the brakes when the wheels lock, put on the brakes again when the wheels start rolling
The safety valve discharges automatically at the pressure of: ✔Correct Answer-150
The air compressor stops pumping air at what psi? ✔Correct Answer-125
If air pressure is not built up within the correct amount of time, then: ✔Correct Answer-Air
pressure may drop to low point while driving, requiring an emergency stop
Parking or emergency brakes of trucks and buses can be legally held on by _____ pressure
✔Correct Answer-spring
If air is not built up within the correct amount of time, then: ✔Correct Answer-Air pressure may
drop to a point while driving, requiring an emergency stop
The air compressor governor controls: ✔Correct Answer-When air is pumped into the air tanks
Excessive use of the service brake results in overheating which can lead to: ✔Correct Answer-
Expansion of the brake drums
When is it OK to leave your truck unattended without applying the parking brakes and choking the
wheels? ✔Correct Answer-never
The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:
✔Correct Answer-the breaking effect of the engine
The parking or emergency brake on a heavy vehicle can only be held in position by something that
cannot leak away, like: ✔Correct Answer-Spring pressure
Is it accepted that too much heat caused by using your brakes too often can also cause: ✔Correct
Answer-Brake to fade or fail
