What is the purpose of brake wear indicators, and how are they checked?

• A. They warn when pad thickness is below serviceable limit; checked by visual inspection or gauge measurement during maintenance.
• B. They monitor rotor wear and predict replacement schedule.
• C. They measure tire pressure at wheel to adjust braking.
• D. They indicate hydraulic fluid level.

Answer: (A)

Brake wear indicators exist to warn you when the brake pad material has worn down to the minimum acceptable thickness, stopping you from losing braking effectiveness or risking rotor damage. They can be built into the pad as a mechanical tab that either scrapes or squeezes the rotor, or they can be electronic sensors that trigger a warning light on the dashboard. Checking them is done during routine maintenance: you inspect the pad thickness and compare it to the vehicle manufacturer’s serviceable limit, often using a brake pad gauge or caliper. If the pad is near or below the limit, it’s time to replace the pads. Some systems also show a warning light when a sensor detects wear. This focus on pad material, rather than rotor wear, tire pressure, or hydraulic fluid level, is why it’s the correct interpretation.