why would my new caliper now be causing a scraping sound when i stop

front or rear ? its probably not the caliper, more like the rotor and pads, have they been replaced? if so the caliper could be frozen? does the car pull to one side while driving or does a wheel get excessively hot ? if neither the sound might be coming from another brake or you have a defective caliper and or pads, were your rotors at least cut if you used the originals?