Serious screeching sometimes

[kevin316i]

Sometimes(mabe once a month on average) I get this really bad screeching noise that sounds like a very bad metal on metal scraping. when driving. It lasts briefly and seems to go when I apply the brakes. The front discs and pads were recently replaced and the rear drums were checked for wear but it still happens.

Could it be particles of dirt getting in under the pads or shoes?

[Simon]

Sounds like a loose chipping or something getting caught somewhere, I used to get it on occasions, sounds like a chipping getting caught between the disc and stone guard.

[kevin316i]

There's plenty of loose chippings on the roads round where I live, so could be whats happening. The joys of living in the country