rear brakes on 99 silverado

i replaced the pads and hit the rotors with sandpaper about 6-7 months ago. everything was good until about 2 weeks ago i hear a grinding noise when braking and most noticably stopping. i found today that the rear passenger pads- outside one is worn down to base and ate into my rotor and the inner is wearing fine but a little uneven. i dont know if its just the pads and rotor or the caliper or whatever else...

Did you lubracte the slide pins at all when you did the brake job, if not the caliper could be sticking which is most likely what has happened.

Like Kenny said you needed to lubricate the caliper slides and pins. Make sure that you use a grease that is designed for brakes. Raybestos makes an excelent brake lube made of silicone, it works very well.

my calipers had locked up from fluid nasty/ contaminted, got new calipers and good now, bleed them, bet black crap comes out.