I assume you are referring to the bolts that join the caliper halves together and not the mounting bolts. Some calipers use aluminum bolts and some use coated steel or stainless steel in an effort to prevent the metals from reacting with one another. If they are stainless or coated steel I would reuse them. If they are aluminum, which are not that common, I would replace them due to fatigue from removal. When I say I, I'm referring to myself and not telling you it is OK to disregard your service manuals advice. For something as important as your brakes, it is best to follow all suggested service procedures outlined in your manual. Your milage may very. good luck