Rear brakes feel rough
 

2003 Silverado
did rear brake job, replaced rotors and pads. after driving for awhile, when i apply brakes the rear acts like the rotors are out of round. gets really rough sometimes. don't know if calipers are sticking or what.
what do you think????

When you say out of round, do you mean like a warped rotor? When you removed the old rotor, did you wire wheel the hub surface before putting new rotor on? Dirt or rust or whatever could be sitting there forcing part of the rotor to not sit perfectly flat. That could potentially be an issue.