Home > Common Errors

  • 950   When a tractor and a trailer are coupled, how much space should there ... Answer
  • 806   When inspect the coupling, you must make certain that there is enough ... Answer
  • 780   In what position should the air line shut off valves be when you check... Answer
  • 731   The air tanks on trailers and converter dollies are filled by:... Answer
  • 695   The emergency air line for:... Answer
  • 665   In order to supply air to the trailer, you must first:... Answer
  • 610   Which one of the following statements about tractor protection valves ... Answer
  • 599   The maximum air released when brakes are released is:... Answer
  • 579   The service air line is controlled by... Answer
  • 569   What is the emergency air line?... Answer
  • 537   For the coupling to be complete for a fifth wheel with a locking lever... Answer
  • 524   Why should you use chocks when parking a trailer without spring brakes... Answer
  • 487   You are driving a combination vehicle when the trailer brakes away, pu... Answer
  • 484   Other names for the Service Air Lines are?... Answer
  • 448   After applying brakes fully max on combination vehicles, what is the a... Answer
  • 446   If you cross connect the two air lines the following will result:... Answer
  • 441   What should the trailer height be before you connect a converter dolly... Answer
  • 435   The service line is for:... Answer
  • 423   Before you back under a semi-trailer in coupling your tractor at what ... Answer
  • 412   When you turn suddenly while pulling doubles, which trailer is most li... Answer
  • 394   Are fully loaded rigs more likely to roll over in a crash than empty r... Answer
  • 391   Why do large combination vehicles that are empty take longer to stop t... Answer
  • 370   The function of the trailer air supply control is:... Answer
  • 369   In order to inspect the coupling you should:... Answer
  • 358   A combination vehicle air brake system should not lose air faster than... Answer
  • 335   The trailer hand valve should be used:... Answer
  • 333   Coupling and uncoupling methods are the same for more common tractor-t... Answer
  • 329   You should swing wide to the left before starting a 90 degree turn:... Answer
  • 327   Which of the following statements about combination vehicles is true?... Answer
  • 327   When should you use the hand valve to park a combination vehicle?... Answer
  • 325   More than half of truck driver deaths in crashes are the result of tru... Answer
  • 302   Why should you not use the trailer hand brake to straighten out a jack... Answer
  • 297   Why should you check your mirrors whenever you apply the brakes hard?... Answer
  • 294   Semi trailers made before 1975 that are equipped with air brakes:... Answer
  • 291   A device which connects the service and emergency air lines from the t... Answer
  • 288   To prevent rollovers, remember to:... Answer
  • 283   When backing a tractor under a trailer, you should expect:... Answer
  • 282   Off tracking is:... Answer
  • 280   What are some things that you can do to avoid getting surprised and ha... Answer
  • 273   When coupling the trailer, back up slowly until:... Answer
  • 268   If you start a trailer skid, you should:... Answer
  • 268   When coupling the glad hands, you should NOT do the following:... Answer
  • 262   You have connected the air lines but have not yet backed under the tra... Answer
  • 256   Large combination vehicles take longer to stop:... Answer
  • 254   Since a sudden movement with your steering wheel can tip a trailer ove... Answer
  • 233   What tells how much pressure the relay valves should send to the trail... Answer
  • 229   Which is true when rolling up the landing gear to complete the couplin... Answer
  • 228   A trailer jackknife is:... Answer
  • 228   What two things can a driver do to prevent rollovers?... Answer
  • 226   The earliest way to notice a trailer skid is:... Answer
  • 225   You should use different methods for uncoupling second and third trail... Answer
  • 215   After you lock the kingpin into the fifth wheel how can you check the ... Answer
  • 214   Which one of the following is controlled by the foot brake?... Answer
  • 214   You should crank the landing gear until:... Answer
  • 209   When traveling under 40 mph, you should follow other vehicles:... Answer
  • 208   You should not back a tractor under a trailer until the whole air syst... Answer
  • 203   You have coupled with a semi trailer. In what position should you put ... Answer
  • 194   Before you back under the trailer, you should be sure that the trailer... Answer
  • 186   Before driving away, how can you always test the trailer brakes?... Answer
  • 184   If you will be pulling doubles where one trailer is more heavily loade... Answer
  • 182   Why should you lock the tractor gland hands (or dummy couplers) to eac... Answer
  • 177   The fifth wheel locking lever is not locked after the jaws close aroun... Answer
  • 171   You should not use the trailer hand valve while driving because:... Answer
  • 165   What happens if (only) the service line comes apart while you are driv... Answer
  • 155   Which amount should a combination vehicle NOT lost air faster than?... Answer
  • 149   The fifth wheel should be checked to see if:... Answer
  • 148   When you make a quick lane change, the trailer only may overturn. What... Answer
  • 148   When you get ready to back under the semi trailer you should line up:... Answer
  • 145   Offtracking occurs when you go around a corner and:... Answer
  • 139   Why must the fifth wheel plate have enough grease?... Answer
  • 137   Why must you be extra careful when bobtailing?... Answer
  • 133   The following two things will help prevent rollovers.... Answer
  • 126   Why should you never unlock the pintle hook with the dolly still under... Answer
  • 125   Looking into the back of the fifth wheel, which part of the kingpin sh... Answer
  • 123   The trailer air supply control:... Answer
  • 120   What is the cause of more than half the truck driver deaths in crashes... Answer
  • 119   After you have coupled the tractor with a trailer where should the lan... Answer
  • 106   If you start a trailer skid, you should:... Answer
  • 102   Before backing up how should you position the tractor in relation to t... Answer
  • 95   Which is true regarding the trailer air supply control?... Answer
  • 93   The dolly tow bar may fly up if you unlock the pintle hook with the co... Answer
  • 85   After you lock the kingpin into the fifth wheel how can you check the ... Answer
  • 80   A kingpin is:... Answer
  • 71   When the wheels of a trailer lock up, what will the trailer tend to do... Answer
  • 66   There are two things that a driver can do to prevent a roll over. They... Answer
  • 53   What should you use to be safe when you park trailers that don't have ... Answer
  • 53   Combination vehicles are usually heavier, longer and require more driv... Answer
  • 42   There are more things to inspect on a combination vehicle than on a si... Answer
  • 26   You should do a walk around inspection when preparing to pull Doubles ... Answer