My Nissan Altima has squeaking rear brakes I suspect it is the caliper. My question to you do I have to buy OEM caliper or can I go aftermarket?
It's more likely to be pads than the calipers, especially if they are worn or low-cost replacements and no anti-noise compound was applied when they were installed.
For future reference please use the subject line for a short description, not your full question. Thank you. (Title edited.)
Also for best answers you should provide all information about your vehicle, as indicated near the top of the page.
@chucktobias I asked if OEM or aftermarket caliper pad was replaced less than a year
@riddick_54 Cheap pads or even decent pads with no anti-squeal compound applied can be prone to squealing. As far as calipers are concerned, as with most parts OEM is preferable but may be cost prohibitive. I've done fine over the years with rebuilt calipers.