Practice question

What is the role of the foot valve (also called the treadle or service brake valve)?

  1. It locks the parking brake
  2. It supplies air to the brake chambers in proportion to how hard the driver presses the pedal
  3. It drains water from the tanks
  4. It controls the trailer air supply

Answer: B — It supplies air to the brake chambers in proportion to how hard the driver presses the pedal

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