Noise after rear disc brake swap

I just did the rear disc brake conversion on my 01 xj and I am now getting a noise under light braking. When I am driving under 30 mph and lightly applying the brakes there is a squealing noise coming from the rear that I haven`t been able to figure out yet. I bled them real good & used all new parts when I did the swap except for the calipers and backing plates. I have no problems braking, the Jeep stops just fine, it is just making the noise. Is it possible that I got bad calipers? It only makes the noise when lightly braking under 30mph. It is fine the rest of the time. Thanks!

Check to see if your backing plates are rubbing on the rotors? I'd bet that they are, either that or the pads haven't bedded in yet.