i'll just be drivin around, and then my front left wheel will makes this tumbling grinding noise. like there is a rock in my brake pads bouncing around on the rotor making noise... it will go away if i push on the brakes. sometimes i gotta push hard, sometimes it will go away with a light tap.if i let it go, it will go on and off.

same thing with me. im wondering if its the pads. it got really bad today. anybody?

check the wheel bearing, check the pads to make sure the anti-rattle shim is on them, make sure none 0f the bolts on the caliper are loose. could also be an incorrect brake pedal or booster push rod setting.