How Often Should Rear Drum Brake Pads Be Replaced?
2 Answers
Drum brakes generally need to be replaced after the vehicle has traveled approximately 100,000 kilometers. How to Determine If Brake Pads Need Replacement: Check the Brake Pad Thickness: When brake pads become very thin, braking performance significantly declines, affecting driving safety. New brake pads are typically around 1.5 cm thick. When the thickness wears down to 0.5 cm, increase the frequency of self-inspection. Once the brake pads wear down to only 0.3 cm, they must be replaced immediately. This is the minimum thickness limit for replacement—do not delay, as it can lead to accidents. Dashboard Warning Light: Most car dashboards have a brake warning light. When this light illuminates, it indicates that the brake pads need inspection. However, if the light is on, it means the pads have reached their wear limit and must be checked immediately. All vehicles have this warning system, but some directly sense the brake pad thickness, while others activate the warning light only after the pads are completely worn and the brake fluid level drops critically. Listen for Sounds: Brake discs are mostly made of iron and can rust after prolonged parking, especially in damp weather. When braking, a slight hissing sound may occur, which usually disappears after driving for a while and applying the brakes a few times. If the sound persists, the brake pads must be replaced immediately. This indicates that the wear indicators on the pads are directly scraping the brake disc, meaning the pads are beyond their limit. In such cases, inspect the brake disc as well, as it may already be damaged. Simply replacing the brake pads may not eliminate the noise, and in severe cases, the brake disc may also need replacement. Brake Response and Pedal Travel: As brake pads wear thin, the car's braking response becomes slower. You may need to press the brake pedal deeper and harder to achieve the same braking effect as before. If you notice that the braking effect weakens in the first half of pedal travel, or the brakes feel soft and less effective, it's time to check if the brake pads need replacement.
The replacement interval for rear drum brake pads mainly depends on actual wear conditions, with no fixed schedule. I usually drive quite smoothly, rarely brake hard, and haven't replaced them even after nearly 80,000 kilometers. But my friend who loves racing on mountain roads replaced them at just 40,000 kilometers. It's recommended to have a mechanic use professional tools to inspect them during maintenance. New brake pads are typically about 12mm thick, and must be replaced when worn down to below 5mm. Drum brakes have a sealed structure, making self-inspection difficult. If you notice longer brake pedal travel or hear metal grinding sounds, immediate action is required. Safety first - when replacing, remember to clean out accumulated dust inside the brake drum.
