Brake Noise?

Started hearing a grinding sound from the brakes, sounds like the drivers front. Actually sounds like metal on metal grinding, but the pads and rotors are new (installed about 4 months ago).

Took off the wheels, and I have almost 3/8 of brake pad left on both inboard and outboard, both pass and drivers side.

Rotors look good too; can't figure out where the noise is coming from....only happens after the van has been driven a few miles, and only as you come to a stop.

Swapped rotors from drivers to pass side, and it seemed to help, but the noise came back this evening.

Any ideas? All I can think of is wheel bearing (pass wheel bearing has been replaced), but the sound / vibration is just screaming 'brake related.'

Doesn't change when I turn or accelerate or slow down; only as I come to a stop.

I've had similiar problems off and on. I too have taken apart the brakes just to find nothing like you did. I've attributed it to just cheap noisy brakes. Taking a file and knocking down the edges just a little bit may also help.