My car was makingan intermittent, horrific grinding sound, like something metal was dragging on the ground (so bad, I stopped to make sure nothing WAS dragging on the ground). That happened four times, when slowing down normally (ie. Not short). Took it to the dealer; they said the rear passenger drum needed to be cut, and they resurfaced the rear drums and sanded the brake shoes to remove grooves. I was able to drop it off a few days later; in the interim, I discovered a bolt in my rear tire, and which I THOUGHT might be the metal sound (ie. The tire was dragging, the bolt was being pulled along the ground). Brought it to the dealership, had the recommended drum/pad work done. After ~300 miles, the horrific, intermittent grinding sound was back (I didn't see a bolt anywhere in my tires, FYI). Didn't happen all the time; happens during normal braking (ie. Not stopping short), and generally only after the car has been driven at least 5 miles. Took it to a mechanic that was recommended to me; he said there was dirt caught in the brakes, cleaned the brakes and adjusted them. Not four miles after leaving, the grinding sound is back. And, now, there's a nice high-pitched rhythmic squeal that appears to be coming from a tire that gets faster as you accelerate. I'm getting very frustrated. Anyone? TIA.
The squeal may be your brake warning in the front discs from wear. Normally it means it's time to replace pads with a squeal. Rust can cause the grinding sound you hear as well. If the drums were cut then the shoes SHOULD have been replaced. Sometimes if the brakes shoes arenot arced to the drum then you get this kind of sound which poses no danger, just makes a noise. But it could be a small piece of rust in the drum causing this as well as one in the front. So have brakes checked again all around car not only rear.