It depends on the car's mileage. Generally, they should be replaced every 50,000 kilometers. Here are methods to check if a car's brake pads need replacement: 1. Thickness - A new brake pad is typically about 1.5cm thick. With continuous friction during use, the thickness gradually wears down. Professional technicians recommend that when visual inspection shows the brake pad thickness has reduced to about 1/3 of the original (approximately 0.5cm), the owner should increase self-inspection frequency and prepare for replacement. 2. Listen for sounds - If a metallic scraping sound (like "iron rubbing iron") accompanies light braking, the brake pads must be replaced immediately. This indicates the wear indicators on both sides of the brake pads are directly contacting the brake disc, proving the pads have exceeded their limit. In such cases, the brake disc should also be inspected during replacement, as this sound often means the disc is already damaged. Simply replacing the pads may not eliminate the noise, and severe cases may require disc replacement. 3. Feel the braking force - As pads thin, braking efficiency decreases. You'll need to press the pedal deeper to achieve the same braking effect that previously required light pressure. When the initial braking response weakens noticeably (many drivers describe this as "soft brakes" or reduced stopping power), it's time to check if the pads need replacement.
