CDL General Knowledge TestAir Brakes (if applicable)Hard
A driver is inspecting the air lines of their commercial vehicle. They discover a section of an air line that is chafed and showing exposed fabric. What immediate action should the driver take?
- AContinue driving, but monitor the air pressure gauge closely.
- BImmediately remove the vehicle from service and have the air line replaced.
- CWrap the chafed section with electrical tape for a temporary fix.
- DApply a sealant or rubber patch to the damaged area.
Show answer & explanationAnswer & explanation
Correct answer: B. Immediately remove the vehicle from service and have the air line replaced.
Exposed fabric on an air line indicates that the outer protective layer has been compromised, making the line susceptible to bursting, especially under high pressure. This is a critical safety defect that requires the vehicle to be immediately removed from service and the air line replaced to prevent total brake failure.
Why the other options are wrong
- A. Continuing to drive with a compromised air line is extremely dangerous and risks total brake failure.
- C. Electrical tape is not a suitable repair for high-pressure air lines and will likely fail.
- D. Sealants or patches are not approved or effective repairs for chafed air lines with exposed fabric.
Compromised Air Line
An air line with exposed fabric due to chafing is severely compromised and requires immediate replacement to prevent brake system failure.
- Indicates structural damage.
- Risk of sudden air loss.
- Vehicle must be taken out of service.
- No temporary repairs are safe.
Memory trick: Fabric showing, air line going, stop the truck, no more flowing.