Wilwood disc brake noise help!!!!!!

[cardreams]

Hey there guys just installed a 4 corner disc brake kit from Wilwood not sure if it's just me but when I first used them they sounded like I was trying to stop a train lol I think it was the black paint wearing off the back disc it went a way after the paint wearied off but now it makes the same noise right before the truck comes to a complet stop any reason why it would do that did I do something wrong ???