Page 1 of 63
CDL Air Brakes EXAM ALL 350 Questions and
Verified Solutions Latest Update This Year
QUESTION: if you do not have automatic tank drain, how often should you drain the oil and
water from the bottom of the compressed air storage air tanks? - ANSWER-at the end of each
day of driving
QUESTION: why drain water from compressed air tanks? - ANSWER-water can freeze in cold
weather and cause brake failure.
QUESTION: during normal driving, spring brakes are usually held back by: - ANSWER-air
pressure.
QUESTION: the air loss rate for a straight truck or bus with the engine off and the brakes on
should not be more than ______ - ANSWER-3 psi in one minute.
QUESTION: to test air service brakes, you should: - ANSWER-brake firmly when slowly moving
forward
QUESTION: total stopping distance for air brakes is longer then that for hydraulic brakes due to
_______ distance - ANSWER-brake lag
, Page 2 of 63
QUESTION: with air brake vehicles, the parking brakes should be used: - ANSWER-whenever you
leave the vehicle unattended
QUESTION: parking or emergency brakes of trucks and buses can be legally held on by pressure:
- ANSWER-spring
QUESTION: the driver must be able to see low air pressure warning which comes on before
pressure in the service tanks falls below ______ psi - ANSWER-60
QUESTION: if your truck or bus has dual parking control valves, you can use pressure from a
separate tank to: - ANSWER-release the spring/emergency parking brakes to move a short
distance.
QUESTION: modern air brake system combine three different systems. they are the service,
parking, and the ________ brakes. - ANSWER-emergency
QUESTION: of the choices below, the first thing to do when a low air pressure warning comes
on is: - ANSWER-stop and safely park as soon as possible
QUESTION: the spring brakes used on tractors and straight truck will bring your truck to a stop
when the air pressure drops bellow ________ psi. - ANSWER-20
, Page 3 of 63
QUESTION: the supply pressure gauge shows how much pressure: - ANSWER-air tanks
QUESTION: the modulating control valve allows you to control the: - ANSWER-spring brakes
QUESTION: before driving a truck or bus with dual air brake system, the pressure in each
system should be at least ______ psi. - ANSWER-100
QUESTION: under ideal conditions a truck with air brakes going 55 mph would require a
stopping distance of: - ANSWER-more then 300 feet
QUESTION: how should you check that the spring brakes come on then air pressure in the
system drops bellow a certain level: - ANSWER-park on level ground, chock the wheels, release
the parking brake when you have enough air pressure, shut the engine off, and repeatedly
press and release the brake pedal
QUESTION: a air brake system is fully charged at _____ psi. - ANSWER-125
QUESTION: excessive use of the service brakes result in overheating which can lead to? -
ANSWER-expansion of the brake drums
QUESTION: air braking takes more time then hydraulic braking because air: - ANSWER-takes
more time to flow through the lines than hydraulic fluid
, Page 4 of 63
QUESTION: if your truck has a dual air system and one of the systems is low on pressure: -
ANSWER-either the front or the rear brakes will not be fully operational.
QUESTION: if your truck has properly functioning dual air brake system and minimum size air
tanks. the air pressure should build from 85-100 within ____ seconds: - ANSWER-45
QUESTION: the braking power of the spring brakes: - ANSWER-depends on the service brakes
being in adjustment
QUESTION: emergency stab brake is when you: - ANSWER-brake as hard as you can, release the
brakes when the wheels lock, put on the brakes again when the wheels start rolling.
QUESTION: the S-cam - ANSWER-forces the brake shoes against the inside of the brake drum
QUESTION: all air brake equipped vehicle have: - ANSWER-a supply pressure gauge
QUESTION: if air pressure does not build to normal within the correct amount of the time, then:
- ANSWER-your air pressure may drop too low during driving, requiring an emergency stop.
CDL Air Brakes EXAM ALL 350 Questions and
Verified Solutions Latest Update This Year
QUESTION: if you do not have automatic tank drain, how often should you drain the oil and
water from the bottom of the compressed air storage air tanks? - ANSWER-at the end of each
day of driving
QUESTION: why drain water from compressed air tanks? - ANSWER-water can freeze in cold
weather and cause brake failure.
QUESTION: during normal driving, spring brakes are usually held back by: - ANSWER-air
pressure.
QUESTION: the air loss rate for a straight truck or bus with the engine off and the brakes on
should not be more than ______ - ANSWER-3 psi in one minute.
QUESTION: to test air service brakes, you should: - ANSWER-brake firmly when slowly moving
forward
QUESTION: total stopping distance for air brakes is longer then that for hydraulic brakes due to
_______ distance - ANSWER-brake lag
, Page 2 of 63
QUESTION: with air brake vehicles, the parking brakes should be used: - ANSWER-whenever you
leave the vehicle unattended
QUESTION: parking or emergency brakes of trucks and buses can be legally held on by pressure:
- ANSWER-spring
QUESTION: the driver must be able to see low air pressure warning which comes on before
pressure in the service tanks falls below ______ psi - ANSWER-60
QUESTION: if your truck or bus has dual parking control valves, you can use pressure from a
separate tank to: - ANSWER-release the spring/emergency parking brakes to move a short
distance.
QUESTION: modern air brake system combine three different systems. they are the service,
parking, and the ________ brakes. - ANSWER-emergency
QUESTION: of the choices below, the first thing to do when a low air pressure warning comes
on is: - ANSWER-stop and safely park as soon as possible
QUESTION: the spring brakes used on tractors and straight truck will bring your truck to a stop
when the air pressure drops bellow ________ psi. - ANSWER-20
, Page 3 of 63
QUESTION: the supply pressure gauge shows how much pressure: - ANSWER-air tanks
QUESTION: the modulating control valve allows you to control the: - ANSWER-spring brakes
QUESTION: before driving a truck or bus with dual air brake system, the pressure in each
system should be at least ______ psi. - ANSWER-100
QUESTION: under ideal conditions a truck with air brakes going 55 mph would require a
stopping distance of: - ANSWER-more then 300 feet
QUESTION: how should you check that the spring brakes come on then air pressure in the
system drops bellow a certain level: - ANSWER-park on level ground, chock the wheels, release
the parking brake when you have enough air pressure, shut the engine off, and repeatedly
press and release the brake pedal
QUESTION: a air brake system is fully charged at _____ psi. - ANSWER-125
QUESTION: excessive use of the service brakes result in overheating which can lead to? -
ANSWER-expansion of the brake drums
QUESTION: air braking takes more time then hydraulic braking because air: - ANSWER-takes
more time to flow through the lines than hydraulic fluid
, Page 4 of 63
QUESTION: if your truck has a dual air system and one of the systems is low on pressure: -
ANSWER-either the front or the rear brakes will not be fully operational.
QUESTION: if your truck has properly functioning dual air brake system and minimum size air
tanks. the air pressure should build from 85-100 within ____ seconds: - ANSWER-45
QUESTION: the braking power of the spring brakes: - ANSWER-depends on the service brakes
being in adjustment
QUESTION: emergency stab brake is when you: - ANSWER-brake as hard as you can, release the
brakes when the wheels lock, put on the brakes again when the wheels start rolling.
QUESTION: the S-cam - ANSWER-forces the brake shoes against the inside of the brake drum
QUESTION: all air brake equipped vehicle have: - ANSWER-a supply pressure gauge
QUESTION: if air pressure does not build to normal within the correct amount of the time, then:
- ANSWER-your air pressure may drop too low during driving, requiring an emergency stop.
