CDL General Knowledge TestAir Brakes (if applicable)Medium
A driver is performing a pre-trip inspection on a vehicle with air brakes. They notice that one of the brake chambers has a slight indentation or 'dishing' on the diaphragm housing. What is the most likely cause of this condition?
- ADamage from external impact.
- BNormal wear and tear over time.
- COver-pressurization of the air system.
- DA faulty air compressor.
Show answer & explanationAnswer & explanation
Correct answer: A. Damage from external impact.
An indentation or 'dishing' on the diaphragm housing of a brake chamber typically indicates physical damage from an external impact. While normal wear occurs, this specific type of deformation points to an external force rather than internal pressure issues or general aging.
Why the other options are wrong
- B. Normal wear usually involves corrosion or cracking, not a specific indentation or 'dishing'.
- C. Over-pressurization would likely cause rupture or bulging, not an indentation.
- D. A faulty compressor affects air supply, not the physical shape of the brake chamber housing directly.
Brake Chamber Indentation
An indentation or 'dishing' on the diaphragm housing of an air brake chamber is usually a sign of external physical damage.
- Indicates external impact.
- Can compromise chamber integrity.
- Requires replacement for safety.
Memory trick: A dent on the chamber, from an impact, that's the danger.