I found this on another site that was reporting the same issue:
Unfortunately this happens more often than you think!
I'm writing to you on behalf of the Global Brake Safety Council (GBSC), which was established with the intent to uphold the highest standards in brake safety.
One of the reasons for the friction material falling off the disc brake plate is the excessive rust build-up between the backing plate and the friction, causing what's known as "rust jacking". This is becoming more of an issue because friction manufacturers are using mill scale steel, commonly referred to as 'black steel', which contains a layer of oxides. This layer, if not properly removed, will be trapped under the friction layer during the manufacturing process. These oxides turn to rust and cause separation between the disc brake plate and the friction (rust jacking), which eventually leads to the friction falling off. This is obviously a major safety concern!
Currently, aftermarket manufacturers of disc brake shoes are self regulated and are expected to engage in 'responsible' manufacturing. With more and more manufacturers moving production to China and India to cut operating cost, they are also cutting corners and jeopardizing the quality of their disc brake shoes and your safety.
The solution is simple: Friction manufacturers MUST use disc brake steel that is free of any mill scale or oxides. This steel is referred to as "pickled and oiled" steel, which goes through a process of acid wash to remove all mill scale and contaminants from the steel.
GBSC has released a detailed report on this safety issue in the brake industry and is currently engaging government and lawmakers to raise awareness on this issue and set legislation for all North American manufacturers to adhere to.
Please visit our website
www.gbscouncil.com for more info and to download the report.
Regards,
GBSC