Alabama CDL General Knowledge Exam
Questions With Detailed Solutions Rated
A+
Oil and water usually collect in compressed air tanks. If you do not have an automatic
tank drain, when should you drain the air tanks? - CORRECT ANSWER-after every
working day
What is the S-cam used for? - CORRECT ANSWER-to put on the brakes
Which of the following makes the total stopping distance for air brakes longer than that
for hydraulic brakes? - CORRECT ANSWER-brake lag distance
The brake system that applies and releases the brakes when the driver uses the brake
pedal is the: - CORRECT ANSWER-service brake system
To make an emergency stop with air brakes, using the stab braking method, you
should: - CORRECT ANSWER-Brake as hard as you can, get off of the brakes when
the wheels lock, get back on the brakes when the wheels start rolling again
Brake lag distance at 55 mph is __________ feet. - CORRECT ANSWER-32 feet
If your vehicle has an alcohol evaporator, it is there to? - CORRECT ANSWER-reduce
the risk of ice in airbrake valves in cold weather
What can legally hold a parking or emergency brake in position for a truck, truck tractor
or bus? - CORRECT ANSWER-spring pressure
, The breaking power of the spring brakes: - CORRECT ANSWER-depends on the
adjustment of the service brake
What should you do before leaving the vehicle unattended? - CORRECT ANSWER-set
the barking brake, remove the keys, and chock the wheels
Under what conditions are front-wheel brakes good? - CORRECT ANSWER-all weather
conditions
If the air tanks are not drained: - CORRECT ANSWER-your brakes may fail because of
water freezing
An anti-lock braking system (ABS): - CORRECT ANSWER-activates when your wheels
are about to lock up
What can cause brakes to fade or fail? - CORRECT ANSWER-excessive use of the
service brake, not relying enough on the engine braking, and brakes being out of
adjustment.
If your vehicle has properly functioning dual air brake system and minimum sized air
tanks, the air pressure should build from 85 to 100 psi within ______ seconds -
CORRECT ANSWER-45
The air compressor will stop pumping air to the air brakes at ______ psi. - CORRECT
ANSWER-125
Excessive heat caused by overuse of the service brakes can cause - CORRECT
ANSWER-the brakes to fade
Questions With Detailed Solutions Rated
A+
Oil and water usually collect in compressed air tanks. If you do not have an automatic
tank drain, when should you drain the air tanks? - CORRECT ANSWER-after every
working day
What is the S-cam used for? - CORRECT ANSWER-to put on the brakes
Which of the following makes the total stopping distance for air brakes longer than that
for hydraulic brakes? - CORRECT ANSWER-brake lag distance
The brake system that applies and releases the brakes when the driver uses the brake
pedal is the: - CORRECT ANSWER-service brake system
To make an emergency stop with air brakes, using the stab braking method, you
should: - CORRECT ANSWER-Brake as hard as you can, get off of the brakes when
the wheels lock, get back on the brakes when the wheels start rolling again
Brake lag distance at 55 mph is __________ feet. - CORRECT ANSWER-32 feet
If your vehicle has an alcohol evaporator, it is there to? - CORRECT ANSWER-reduce
the risk of ice in airbrake valves in cold weather
What can legally hold a parking or emergency brake in position for a truck, truck tractor
or bus? - CORRECT ANSWER-spring pressure
, The breaking power of the spring brakes: - CORRECT ANSWER-depends on the
adjustment of the service brake
What should you do before leaving the vehicle unattended? - CORRECT ANSWER-set
the barking brake, remove the keys, and chock the wheels
Under what conditions are front-wheel brakes good? - CORRECT ANSWER-all weather
conditions
If the air tanks are not drained: - CORRECT ANSWER-your brakes may fail because of
water freezing
An anti-lock braking system (ABS): - CORRECT ANSWER-activates when your wheels
are about to lock up
What can cause brakes to fade or fail? - CORRECT ANSWER-excessive use of the
service brake, not relying enough on the engine braking, and brakes being out of
adjustment.
If your vehicle has properly functioning dual air brake system and minimum sized air
tanks, the air pressure should build from 85 to 100 psi within ______ seconds -
CORRECT ANSWER-45
The air compressor will stop pumping air to the air brakes at ______ psi. - CORRECT
ANSWER-125
Excessive heat caused by overuse of the service brakes can cause - CORRECT
ANSWER-the brakes to fade
