when my ebrake is off, I can wiggle the two sides of the caliper on my passenger side rear brake. this causes a loud clattering sound as I drive over rough roads, similar to having a trailer hooked up. a friend of mine took the two halfs of the caliper apart and lubed up the slide pins. after that the sound completely when away for about a month but has since returned. I know the slide pins are suppose to be snug inside the caliper. question is, what exactly is wrong with the calipers? is the pin worn down or is it something to do with the outer most side of the caliper? should I buy a new caliper or can I replace just the slide pins?