CDL Air Brakes EXAM ALL 250 Questions and Verified Solutions Latest Update This Year

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CDL Air Brakes EXAM ALL 250 Questions and
Verified Solutions Latest Update This Year

QUESTION: Your truck has properly functioning dual air brake system and minimum size air
pressure should build from 85-100 psi within - seconds ? - ANSWER-45




QUESTION: If your truck or bus has dual parking brakes control valves you can pressure from a
separate tank to ? - ANSWER-Release the spring emergency parking brakes to move a short
distance




QUESTION: the proper method of braking when going down long and or steep grades after
selecting the proper gear is to brake till your speed is about - mph below your 'safe' speed, and
then release your brake ? - ANSWER-5




QUESTION: It is not safe to drive a vehicle that has brake drums (or discs) with cracks or that are
thinner than the manufacturers specifications, generally this will be - inch ?. - ANSWER-1/4




QUESTION: A supply pressure gauge tells you how much pressure is in the ? - ANSWER-Air tanks




QUESTION: Air braking takes more time than hydraulic braking because air ? - ANSWER-Takes
more time to flow through the lines than hydraulic fluid

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QUESTION: During normal driving, spring brakes are usually held back by ? - ANSWER-Air
pressure




QUESTION: Some air brake systems have an alcohol evaporator What may happen if you don't
keep the unit filled with alcohol ? - ANSWER-ice may form in the air storage tanks and cause the
brakes to fall




QUESTION: The brake system that applies and releases the brakes when the driver uses the
brake pedal is the - brake system ? - ANSWER-service




QUESTION: which of the following about antilock braking systems is true? - ANSWER-Abs
changes the way you brake in Emergencies




QUESTION: in air brake vehicles ,the parking brakes should be used ? - ANSWER-Any time the
vehicle is parked




QUESTION: If your antilock braking system is not working you should ? - ANSWER-Drive
normally, but get the system serviced soon




QUESTION: Excessive use of the service brakes results in overheating, which can lead to ? -
ANSWER-Expansion of the brake drums

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QUESTION: your truck or bus has a dual air brake system . if a low air pressure warning comes
on for only one system you should ? - ANSWER-stop and safely park. continue only after the
system is fixed




QUESTION: The air compressor should stop pumping prior to reaching a_psi ? - ANSWER-130




QUESTION: The use of air brakes on a downgrade is only a supplement to the ? - ANSWER-
braking affect of the engine




QUESTION: In air brake vehicles the parking brakes should be used ? - ANSWER-Any time the
vehicle is parked




QUESTION: Excessive heat in the brakes can cause the ? - ANSWER-Brakes to fade or fall




QUESTION: To test air service brakes you should ? - ANSWER-Brake firmly when slowly moving
forward




QUESTION: You should know your brakes are fading when ? - ANSWER-you have to push the
brake pedal harder to control speed on a downgrade

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QUESTION: The air brake system for a straight truck or bus should not leak at a rate of more
than - psi per minute with the engine off and the brakes released ? - ANSWER-2




QUESTION: The braking power of the spring brakes ? - ANSWER-Depends on the service brakes
being in adjustment




QUESTION: If your truck has a dual air brake system and one of the systems is low on pressure ?
- ANSWER-Either the front or rear brakes will not be fully operational




QUESTION: The parking or emergency brakes of trucks and buses can be legally held on by -
pressure ? - ANSWER-spring




QUESTION: Modern air brake systems are three different systems combined together. They
arethe service, parking, and the - brakes ? - ANSWER-Emergency




QUESTION: The air supply pressure gauge shows how much pressure ? - ANSWER-Is in the air
lines




QUESTION: If you must make an emergency stop, brake so you ? - ANSWER-Can steer and your
vehicle stays in a straight line