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Practice quizzes / NJ CDL Combination Practice Questions - New Jersey CDL Combination Vehicles Test Exam / Question 147994
Practice question

During a New Jersey tractor-trailer trailer air tanks review, why drain trailer air tanks?

  1. Disconnect the electrical cord
  2. Assume the fifth wheel is locked
  3. Use the parking brake while moving
  4. To remove water and oil

Answer: D — To remove water and oil

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

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