As the title states, my car has developed a grinding noise from the rear driver's side wheel when the brake is depressed (such as when I arrive at a red light).

When the light turns green and i hit the gas, the grinding noise persists and then fades away after a few seconds of driving. I assume something is up with the brakes obviously, but is it that the pads are low or the rotors are done? I've had the pads replaced but not long enough ago that they should be worn out. Besides, my front pads still stop the car quite well, and no other noises are emitted from other wheels.

Please help me discern whether the noise stems from a problem with the pads, rotors, or something else (such as low brake fluid causing the pad to collapse and be held to the rotor?).

 

The rear pads are past the wear material and what you are hearing is metal on metal. If the pads were replaced recently (all depends on what you consider recent), you might have a sticking caliper, which is why the pads might have worn down quicker than you would expect.

If the rotor surface has been scarred a lot, you may want to consider replacing the rotors when you replace the pads. Also make sure the caliper isn't binding - o/wise you'll have the same problem again.

 

If the pads were replaced "not too long ago" it's most likely a stuck caliper; it wears down one of the two brake pads.

 

if its an awful grinding noise, you calipers are probably frozen and your rotors are being eaten by the more than worn down pad. in that case, you'd have to replace the rotors, calipers, pads.

 

Ya, that's worst case scenario....