NC CDL COMBINATION VEHICLES LATEST UPDATE

NC CDL COMBINATION VEHICLES 2024- 2025 LATEST UPDATE You are coupling a semi-trailer to your tractor but have not yet backed under, the trailer is at the right height when: - CORRECT ANSWER It will be raised slightly when the tractor is backed under it. You should not back a tractor under a trailer until the whole air system is: - CORRECT ANSWER At normal pressure. Which part of the kingpin should the locking jaws close around? - CORRECT ANSWER The shank. When you get ready to back under the semi-trailer you should line up: - CORRECT ANSWER Directly in front of the trailer. How should you test the tractor semi-trailer connection for security? - CORRECT ANSWER Pull gently forward in low gear against the locked trailer brakes, then look at it carefully. When should you use the hand valve to park a combination vehicle? - CORRECT ANSWER Never. You supply air to the trailer tanks by: - CORRECT ANSWER Pushing in the trailer air supply valve. Why should you be sure that the fifth wheel plate is greased as required? - CORRECT ANSWER To prevent steering problems. NC CDL COMBINATION VEHICLES 2024- 2025 LATEST UPDATE 2 | P a g e 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: - CORRECT ANSWER Applying and releasing the trailer brakes and listening for brake sounds. There are two things that a driver can do to prevent a rollover. They are: (1) Keep the cargo as close to the ground as possible; and (2): - CORRECT ANSWER Go slowly around turns. Before you back under a trailer, make sure the: - CORRECT ANSWER Trailer brakes are locked. If the service air line comes apart while you are driving a combination vehicle, but the emergency line stays together, what will happen right away? - CORRECT ANSWER Nothing is likely to happen until you try to apply the brakes. The air leakage rate for a combination vehicle (engine off, brakes on) should not be more than ___ PSI per minute. - CORRECT ANSWER 4 In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true? - CORRECT ANSWER If the trailer has not spring brakes, you can drive away, but you will not have trailer brakes. Why should you lock the tractor glad hands (or dummy couplers) to each other when you are not towing a trailer? - CORRECT ANSWER It will keep dirt and water out of the lines.