CDL Combination Vehicles TestCombination Vehicle Air BrakesEasy

During a pre-trip inspection, a driver observes that the air compressor drive belt is frayed and has several cracks. What is the most appropriate action?

  1. ATighten the belt tension to compensate for the fraying and cracks.
  2. BContinue driving, but plan to replace the belt at the next scheduled maintenance.
  3. CImmediately replace the drive belt before operating the vehicle.
  4. DApply belt dressing to temporarily fix the damage and continue the trip.
Show answer & explanation

Correct answer: C. Immediately replace the drive belt before operating the vehicle.

A frayed and cracked air compressor drive belt is a critical defect. If this belt fails, the air compressor will stop working, leading to a loss of air pressure and eventually loss of braking capability. It must be replaced immediately for safety.

Why the other options are wrong

  • A. Tightening a damaged belt may cause it to fail sooner or damage other components; replacement is the only safe solution.
  • B. Driving with a damaged compressor belt is highly dangerous due to potential loss of air pressure and brakes.
  • D. Belt dressing is not a repair for frayed or cracked belts; it's a temporary measure for squealing and won't prevent failure.

Air Compressor Drive Belt Inspection

Regular inspection of the air compressor drive belt for damage (fraying, cracks, excessive wear) is crucial, as a failed belt will lead to loss of air pressure and braking capability.

  • Inspect for fraying, cracks, and proper tension.
  • Failure leads to loss of air pressure.
  • Requires immediate replacement if damaged.

Memory trick: Frayed belt, no air, no brakes, beware!

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