What does brake lining wear mean?

Hello, It means you wither need your brake pads (brake linings) or brake shoes (brake linings) replaced. Just a standard brake job, could be the front or rear. Here is the thing with Mercedes brakes: they use sensors to show wear instead of the annoying squeaking brake wear indicator that you have to touch the brakes to stop. So, you could just have a bad brake wear indicator, but that is far from likely. If you replace the brakes yourself, be advised that you also have to replace the brake wear indicator sensors as well, or the message will never go away