Practice question

Which choice is safest and most consistent with Minnesota/FMCSA guidance on trailer air supply control?

  1. Back or turn faster so the trailer responds sooner
  2. Use the trailer hand valve for normal stopping
  3. Skip the visual check if the tug test feels normal
  4. push in to supply trailer air and pull out for emergency brakes

Answer: D — push in to supply trailer air and pull out for emergency brakes

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: MN CDL Combination Practice Questions - Minnesota CDL Combination Vehicles Test Exam →