Calipers rarely need rebuilt, in my experience. It’s usually supporting hardware that causes issues (i.e. sliding pins, hoses, etc.).
This condition usually (in my experience) means the sliders are binding.
This is indicated by:
- the wearing of one side of vehicle more than the other
- the wearing of one of the pads on that disk more than the other
This is because the caliper is massively powerful in squeeze, and pulls the caliper over on the sliders until the brake squeezes, but then does not release properly because there’s very, very little power (i.e. NO hydraulic power; just elastomer power) behind the release. So it rubs and wears that pad.
Of course, I’m making a LOT of assumptions, but they’re based on the averages in the automotive world (e.g. MOST vehicles out there use sliding calipers, etc.)…
EDIT: oops, I took too long, and Kevin said the same thing, basically.