CDL Class A Combination Vehicle Test Flashcards

CDL Class A Combination Vehicle Test Flashcards When should you use the hand valve to park a combination vehicle?A) to park at loading docksB) neverC) to park on a gradeD) in sub-freezing temperature B Which one of the following is controlled by the foot brake?A) the service air lineB) the emergency air lineC) the shut off valveD) the hose coupler A You should not back a tractor under a trailer until the whole

air system is:A) between 60 and 80 psiB) emptyC) bled

down to half the maximum pressureD) at normal pressure D The air leakage rate for a combination vehicle (engine off, brakes off) should be no more than ____ psi per minute.A)

1B) 2C) 3D) 4

C When you get ready to back under the semi trailer you

should line up:A) about 12 degrees off the line of the

trailerB) the kingpin to engage the driver's side locking jaw firstC) exactly one trailer length in back of the trailerD) directly in front of the trailer D You have coupled with a semi trailer. In what position should you put the front trailer supports before driving away?A) 3 turns off the top with the crank handle secured in it's bracketB) fully raised with the crank handle secured in its bracketC) raised 1/2 way with the crank handle removedD) none of the above B After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is

done by:A) applying and releasing the trailer brakes and

listening for brake soundsB) lifting the brake pedalsC) turning on the parking brakes from the cabD) releasing the tractor brakes A If you start a trailer skid you should...A) step on the brakes quicklyB) release the brakes to get traction backC) use the trailer hand brakeD) slowly apply pressure to the brakes B The earliest way to notice a trailer skid is...A) by feeling the pull on your steering wheelB) by feeling a jerking in the back of the tractorC) by seeing it in your mirrorsD) by hearing the squeal from the tires C Air lines on a combination vehicle are often colored to keep them from getting mixed up. The emergency line is ____; the service line is____.A) Red, blueB) Blue, redC) Black, yellowD) Depends on the type of trailer A

The hand valve should be used:A) to test the trailer

brakesB) only when the trailer is fully loadedC) only in emergenciesD) only with the foot brake A

You supply air to the trailer tanks by:A) pushing in the

trailer air supply valveB) pulling out the trailer air supply valveC) connecting the blue line to the red lineD) connecting the service line glad hand A When you are traveling under 40 mph, you should follow other vehicles...A) only during the dayB) with a distance of one second for every ten feet of your vehicle lengthC) with a distance of one second for every twenty feet of your vehicle lengthD) as close as possible so others dont cut in B You are coupling a tractor and semi trailer and have connected the air lines. Before backing under the trailer,

you should:A) make sure that the trailer brakes are offB)

supply air to the trailer system, then pull out the air supply knob to lock the trailer brakesC) apply the brakes twice to alert othersD) all of the above B Which of these statements is true?A) light vehicles need more braking power to stop than heavy onesB) always delay braking a heavy vehicle until you have no other choiceC) "bobtail" tractors can take longer to stop than a combination vehicle loaded to the maximum gross weightD) none of the above C The trailer should be lowered so that...A) the trailer is far above the fifth wheelB) the tractor strikes the nose of the trailerC) you can use the landing gear to make any adjustmentsD) it's raised slightly when the tractor's backed under it D If you cross connect the two air lines the following will result...A) nothing, the lines are interchangeableB) you will not have air going to the trailer brakesC) your tractor brakes will lock upD) you could not move the tractor B You are coupling a tractor to a semi trailer and have backed up but are not under it. What should you hook up before backing under?A) the safety chainB) the electrical service cableC) nothing, back up and lock the fifth wheelD) the emergency and service air lines D When you inspect the coupling, check to ensure that...A) there's a little slack in the air linesB) there's no slack in the air linesC) the landing gear handle is hanging freeD) the electrical cable is unplugged A Which one of the following statements about tractor protection valves in NOT true?A) it keeps air in the tractor in the event the trailer air leaksB) it is controlled by the

trailer air supply valve in the cabC) when it closes it allows air to leak from the tractor lineD) it will close automatically if air pressure is low C