CDL General Knowledge TestCombination Vehicles (if applicable)Medium
When inspecting the air lines (hoses) connecting the tractor to the trailer, what is the most critical defect that would require immediate repair or removal from service?
- ABulges or cuts that expose the fabric or wire reinforcement.
- BAccumulation of dirt or grime on the hose surface.
- CMinor discoloration or fading of the hose color.
- DLight surface scuffing that does not penetrate the outer layer.
Show answer & explanationAnswer & explanation
Correct answer: A. Bulges or cuts that expose the fabric or wire reinforcement.
Bulges or cuts that expose the internal reinforcement layers of an air line indicate a severe compromise to its structural integrity. This can lead to sudden hose failure, resulting in a complete loss of air pressure to the trailer brakes, which is an immediate safety hazard.
Why the other options are wrong
- B. Dirt and grime should be cleaned but do not represent a structural defect requiring immediate repair.
- C. Discoloration is cosmetic and does not affect function.
- D. Light surface scuffing is generally acceptable unless it shows signs of deeper damage.
Air Line Integrity
The structural soundness and leak-free condition of the air hoses connecting the tractor and trailer, essential for proper brake operation.
- Hoses must be free of cuts, bulges, and chafing.
- Reinforcement exposure indicates critical damage.
- Any severe damage requires immediate repair.
Memory trick: If you see the guts, it's a critical cut.