Practice question

Why verify both trailer parking brake and service brake operation after coupling?

  1. Both test the same hose only
  2. Parking brakes replace service brakes
  3. Parking brakes hold when parked; service brakes stop during foot-brake applications
  4. Service brakes are only for uncoupling

Answer: C — Parking brakes hold when parked; service brakes stop during foot-brake applications

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