Why do your brake pads make noise? Human and product causes explained

Category Industry Insights Published 2026-04-02 Source www.boerfibre.com

Abstract

This article explains the causes of brake pad noise, dividing them into human factors and product factors. Under human factors: after replacing original pads, noise often turns out to have been caused by the original pads already having scratched the disc — repair shops usually do not check the disc for scratches when fitting new pads; the recommended handling is to check the disc first, suggest resurfacing or replacing it if scratched, and record the driver's written consent on the repair order if they decline.

It then covers cases where a smooth disc still squeals after new pads: the mechanic fitted the pads offset (partial friction marks visible) — remove and reinstall; friction-block sizes differ between manufacturers of the same model, by up to 3 mm, so an over-size pad on a disc worn by smaller pads still squeals — resurface the disc or run in until the bedding pattern matches; sudden noise after a period of driving may come from hard debris (gravel, iron scrap) caught between pad and disc, which also scratches the disc; rattling rather than squeaking points to loose pad accessories — re-fasten or replace. On product factors, the article notes that national rules already ban asbestos pads, while semi-metallic asbestos-free pads run harder.

Key facts

  • Human factor 1: original pads often already scratched the disc (the article estimates over 50% of cases) — inspect the disc before fitting new pads
  • Human factor 2: offset installation — reinstall the pads squarely
  • Dimension mismatch: friction-block width can vary by up to 3 mm between manufacturers of the same model
  • Debris noise: gravel or iron scrap caught between pad and disc causes noise and disc damage
  • Rattling noise: check loose pad accessories
  • Product note: asbestos pads are banned in China; semi-metallic asbestos-free pads are harder

The original article is in Chinese; see the Chinese version for the full text. This page provides the English title, abstract and key facts only — translated and compiled from the original, without full verbatim translation.