What is likely to be causing this disc wear? Ford Fiesta ST, 2016
Fiesta ST, 2016. 1.6L. The discs and pads were replaced just under a year ago, and now both rears are looking like this, and make a grinding metal noise when moving along (even without applying the brakes.)
A local garage had a look at it for me, but all they said was that they need replacing, didn’t take anything off except the wheels. I will get them replaced, but I thought I’d see what a likely cause is, since I don’t want to replace discs and pads and have the same issue happen again.