• ASD Combination Study Material

  • This is the study material for the Combination Knowledge test. Please study it until you are comfortable with the material, and then proceed to the practice tests.

  • The best way to tell if your trailer has started to skid is to*
  • You have pushed in the trailer supply valve. You should not move the tractor until the whole air system is*
  • Which part of the kingpin should the locking jaws close around?*
  • Under good driving conditions, you should leave at least one second of space between your vehicle and the vehicle ahead for every ____ feet of your vehicle's length*
  • Which of these vehicles off-track the most?*
  • A tractor with a( n ) _____ trailer requires the shortest stopping distance*
  • A trailer is most likely to jackknife when it is*
  • When checking that the trailer is securely coupled to the tractor,  the landing gear should be*
  • If you are coupled with a semitrailer, where should the front trailer supports be before driving away?*
  • Compared to a straight truck or bus, there are _____ things to inspect on a combination vehicle*
  • You want to inspect the trailer supports. You should place the tractor transmission in which gear after you have uncoupled the trailer?*
  • There are two things that can prevent a rollover. They are: 1. Keep the cargo as close to the ground as possible; and 2.*
  • The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:*
  • When you are uncoupling a loaded trailer, lower the landing gear until it*
  • The front trailer supports are up and the trailer is resting on the tractor. Make sure:*
  • Glad hands are used to connect the*
  • How much space should be between the upper and lower fifth wheel after coupling?*
  • You should not back a tractor under a trailer until the whole air system is*
  • You are coupling a semitrailer to your tractor but have not backed under it. The trailer is at the right height when*
  • When checking the trailer's emergency brakes, the tractor protection control valve should be placed in the ______ position*
  • Which statement is true?*
  • In general, the higher your truck's "center of gravity" the*
  • You are coupling a tractor to a semitrailer. You have backed up but are not under it. What should you hook up before backing under the semitrailer*
  • Air and electric lines from the tractor to the trailer should be*
  • If you cannot make a turn without entering another traffic lane, you should*
  • When should you use chocks to park a trailer not equipped with spring brakes?*
  • When coupling, the proper position of the fifth wheel is*
  • To stop a trailer skid you should*
  • After you lock the kingpin into the fifth wheel, you should check the connection by pulling*
  • You are uncoupling a trailer. After you shut off the trailer air supply and lock the trailer brakes, you should*
  • To unlock the fifth wheel, pull the release handle to the _________ position*
  • For a coupling to be completed, the safety catch for the fifth wheel locking lever must be*
  • Before you back a under a truck trailer, make sure the*
  • After you connect the air lines, but before you back under the trailer, you should*
  • Why should you be sure that the fifth wheel plate is greased as required?*
  • After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in the _______ position*
  • After you have coupled the trailer, you should begin raising the landing gear by using the ________ gear.*
  • When backing a tractor under a trailer you should*
  • Why should you lock the air line glad hands to each other (or dummy couplers) when you are not towing a trailer?*
  • When you get ready to back under a semitrailer, you should line up*
  • After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. You do this by*
  • When should you get out of your vehicle when backing with a trailer?*
  • What should you do if your vehicle gets stuck on a raised railroad-highway crossing?*
  • Semitrailers made before 1975 that are equipped with air brakes:*
  • When should you use the hand valve to park a combination vehicle?*
  • The hand valve should be used:*
  • You are driving a combination vehicle. If the service air line comes apart but the emergency line stays together, what will happen right away?*
  • Air lines on a combination vehicle are often colored to keep from getting them mixed up. The emergency line is ______; The service line is ______.*
  • When connecting the glad hands, press the two seals of the couplers together at a degree angle to one another*
  • You supply air to the trailer tanks by:*
  • The trailer air supply control (or tractor protection valve control) should automatically close when the air pressure falls to between ________ psi*
  • You are driving a combination vehicle. The trailer breaks away and pulls apart both air lines. You would expect the trailer brakes to come on and the:*
  • What will happen if the air lines are crossed when you hook up to an old trailer?*
  • When driving a set of doubles, it is necessary to close the _______ shut-off valve in the last trailer*
  • Loss of air pressure in the emergency line causes:*
  • You have a major leak in the service line and you put on the brakes. Service air pressure will escape and cause the:*

  • This is the study material for the Combination Knowledge test. Please study it until you are comfortable with the material, and then proceed to the practice tests.

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