CDL Air Brakes |Complete Questions
with Graded A+ Answers
Air loss in a straight truck or bus should not be more than how much PSI with the engine off and the
brakes on?
3 PSI in one minute
To make an emergency stop with air brakes, using the stab braking method, you should
Brake as hard as you can
get off brakes when wheels lock
get back on brakes when wheels start rolling again
All vehicles with air brakes must have what signal?
Low air pressure warning signal
It is accepted that too much heat caused by using your brakes too often can also cause what?
brake to fade or fail
When is it ok to leave your truck unattended without applying the parking brakes and choking the
wheels?
Never
You should know that your brakes are fading when you have to do what?
push harder on the brake pedal to control your speed on a downgrade
The safety valve discharges automatically at what pressure?
150
What is a dual airbrake system?
2 brake system
one operates front brakes
one operates back brakes
If air pressure is not built up within the correct amount of time, then what will happen?
air pressure may drop to a low point while driving, requiring an emergency stop
How often should you drain air tanks?
Daily
A slack adjusters free play needs to be adjusted if it is more than about how many inches when you
pull hard on it?
, 1 inch
In ideal conditions, a truck or bus with an air brake going at 55 mph would require a stopping distance
of how many feet?
more than 300 feet
If air pressure is not built up within the correct amount of time, then what will happen to the air
pressure?
drop to a low point while driving
requiring an emergency stop
It is accepted that too much heat caused by using your brakes too often can also cause what?
Brake to fade or fail
What does the governor control?
when air compressor will pump into air storage tanks
To make an emergency stop with air brakes, using the stab braking method, you should do what?
Brake as hard as you can
get off brakes when wheels lock
get back on brakes when wheels start rolling
The driver must be able to see a low air pressure warning which comes on before pressure in the
service air tanks falls below what PSI?
60
The use of brakes on a long steep downgrade is only a supplement to the braking effect of the engine
True
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure
drops below what PSI?
60
What do air brakes use to make the brakes work?
Compressed Air
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
Spring Pressure
When you put on the brakes by pushing down the brake pedal, what happens?
Air pressure is applied to the brake pads
with Graded A+ Answers
Air loss in a straight truck or bus should not be more than how much PSI with the engine off and the
brakes on?
3 PSI in one minute
To make an emergency stop with air brakes, using the stab braking method, you should
Brake as hard as you can
get off brakes when wheels lock
get back on brakes when wheels start rolling again
All vehicles with air brakes must have what signal?
Low air pressure warning signal
It is accepted that too much heat caused by using your brakes too often can also cause what?
brake to fade or fail
When is it ok to leave your truck unattended without applying the parking brakes and choking the
wheels?
Never
You should know that your brakes are fading when you have to do what?
push harder on the brake pedal to control your speed on a downgrade
The safety valve discharges automatically at what pressure?
150
What is a dual airbrake system?
2 brake system
one operates front brakes
one operates back brakes
If air pressure is not built up within the correct amount of time, then what will happen?
air pressure may drop to a low point while driving, requiring an emergency stop
How often should you drain air tanks?
Daily
A slack adjusters free play needs to be adjusted if it is more than about how many inches when you
pull hard on it?
, 1 inch
In ideal conditions, a truck or bus with an air brake going at 55 mph would require a stopping distance
of how many feet?
more than 300 feet
If air pressure is not built up within the correct amount of time, then what will happen to the air
pressure?
drop to a low point while driving
requiring an emergency stop
It is accepted that too much heat caused by using your brakes too often can also cause what?
Brake to fade or fail
What does the governor control?
when air compressor will pump into air storage tanks
To make an emergency stop with air brakes, using the stab braking method, you should do what?
Brake as hard as you can
get off brakes when wheels lock
get back on brakes when wheels start rolling
The driver must be able to see a low air pressure warning which comes on before pressure in the
service air tanks falls below what PSI?
60
The use of brakes on a long steep downgrade is only a supplement to the braking effect of the engine
True
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure
drops below what PSI?
60
What do air brakes use to make the brakes work?
Compressed Air
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
Spring Pressure
When you put on the brakes by pushing down the brake pedal, what happens?
Air pressure is applied to the brake pads
