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Practice quizzes / USPS MVO Exam Practice Questions - USPS Exam 220 230 240 - Motor Vehicle Operator Tractor Trailer Operator (Driving Experience Assessment) Exam / Question 195199
Practice question

The yellow diamond-shaped push-pull valve on the dash controls the:

  1. Tractor service brakes
  2. Tractor parking brake (spring brakes)
  3. Trailer air supply
  4. Engine cooling fan

Answer: B — Tractor parking brake (spring brakes)

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

Practice more: USPS MVO Exam Practice Questions - USPS Exam 220 230 240 - Motor Vehicle Operator Tractor Trailer Operator (Driving Experience Assessment) Exam →
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