How to Solve the Problem of Harsh Noise from Motorcycle Rear Brake?

[VonMaggie]

There is oil contamination between the brake shoes and the brake drum of the drum brake. Clean the brake drum and brake shoes with alcohol to remove the oil contamination. Use 800# sandpaper to polish the surface of the brake shoes to increase the friction of the brake shoes.

[JamesonAnn]

I've been riding motorcycles for over a decade, and screeching rear brakes are all too common. Last time my little scooter sounded like nails on a chalkboard—it was downright annoying. When I took it apart, the brake pads were worn down to a thin sliver, with the metal backing plate scraping directly against the rotor. No wonder it screamed! I promptly spent about a hundred bucks on new brake pads and took the time to scrub off any sand or metal debris from the brake disc. The noise vanished immediately after the replacement. A word of advice: don't ignore unusual brake noises—it could mean your pads are already at the safety limit. Delaying further risks lock-ups during emergency stops. Pay extra attention after the rainy season, as moisture can harden the brake pad surface and cause squealing.

[LeDominic]

For motorcycle brake squealing issues, I recommend troubleshooting from simple to complex. First, use a high-pressure water gun to rinse the rear brake disc thoroughly for three to five rounds—dust and grease might be the culprits. If the noise persists, remove the brake caliper, take out the brake pads, and sand them back and forth with sandpaper several times to remove the shiny oxidized layer on the surface. Reinstall and test; if it still squeals, you’ll need to replace the pads—a good brand can be bought online for around 50 yuan. Remember to regularly apply grease to the brake pins to prevent rust. Once, I had a stuck pin that caused uneven pad wear and squealing. After adjusting the clearance and test-riding, the problem should be 80% resolved.

[SpencerRose]

Squeaky brakes are usually caused by vibration frequencies. When metal brake pads encounter hard objects or high-temperature surfaces, they may slip, generating high-frequency squeals due to instant friction. Try filing a 45-degree chamfer on the edges of the brake pads to disrupt that resonant frequency point. If that doesn't work, apply specialized anti-squeal paste on the back of the brake pads to separate the metal contact surfaces. I've also found that brake fluid can play a role—old fluid with high water content is prone to vapor lock, causing slow retraction of caliper pistons and leading to dragging and noise. These methods can solve about 90% of brake noise issues.