I have just come back from a holiday in The Lakes, staying round Keswick and drove on some wonderful roads, most of which where spoilt by slow drivers braking every time there is a straight or a bend in the road, not to mention a passing car. Anyhow, I digress. One day out and about I was happily driving when suddenly I heard this grinding, metal on metal - fingernails down a black board type of noise. I stopped to take a look, could not see anything, then drove the car backwards then forward and again slowly to hear this horrendous noise. Luckily there was a car garage near by and stopped in there. Spoke to the mechanic and said it was stones caught between the disc and the backing plate/shield. So much that is damaged the disc and needed replacing as they were…well, put it this way, I got my monies worth.
Something I had not planned to spend money on holiday. Its done now.