First about the sound: the rumbling/grinding/pulsing noise from the front brakes sounds like when you drive over those stop-light or stop-sign warning bumps. It is intermittent. I can go a few days without the brakes making this sound. I've also noticed that sometimes, it seems to make this sound when I am pressing on the brakes only half way, not fully depressed. Other times the sound will start half-way through the pressing of the brakes and will continue until the brakes are fully depressed.

I had my 60,000 mile service in April and was told there was still 30% on my front brakes. I had no brake work done. A couple of weeks after, the front brakes began making this sound, intermittently. I brought my car into the dealer (and the guy treated me like I was some kind of car hypocondriac), and was sheepishly told once they saw there was a problem, that because of rust erosion on the rotor, a rubber piece had moved causing something or other. (Sorry, I don't know all the specific terms and parts). Well, the whole front brake system/assembly needed to be replaced (rotors, calipers, discs and pads), which I had them do that day.

A few days afterwards, the sound came back, went away for several days, now has returned. It is still intermittent. What is this sound? Do I need to bring my car in again to be serviced at $105 an hour for labor, after having paid $1,000 for a whole new front break system? Is there a warranty on the brake system parts? Please help.