FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsEasy
During a brake inspection, a technician notices the wear indicator pin on a multiple-disc brake assembly is flush with the housing when the brake is applied. This indicates that the
- Abrake linings are worn to their replacement limit
- Bparking brake valve is leaking internally
- Cbrake needs bleeding to remove trapped air
- Dbrake pressure is set too high
Show answer & explanationAnswer & explanation
Correct answer: A. brake linings are worn to their replacement limit
Wear indicator pins protrude from the brake housing when applied; as linings wear, the pin retracts. When the pin is flush or below the specified mark with the brake applied, the linings are worn to the replacement limit.
Why the other options are wrong
- B. A leaking parking valve would cause pressure loss, not affect the wear pin position.
- C. Bleeding relates to hydraulic air, not lining wear indication.
- D. Excess pressure isn't indicated by wear pin position.
Brake Wear Indicator Pin
A pin on multiple-disc brakes that shows lining wear by how far it protrudes when the brake is applied.
- Pin protrudes less as linings wear
- Flush or below-limit position means replacement needed
- Always checked with brake applied, per manufacturer's chart
Memory trick: Flush pin = finished brake