just installed new rotors and pads. front are metal pads with x-drilled rotors. rears are OEM kinda stuff. also new thrust arms in.

didn't have rotor set screws (old ones were destroyed when extracted cuz they were impossible to get out) - so both front rotors were kinda held up and pushed in place when we put the wheels on.

when i brake now, not 100% of the time but pretty consistently, i'll get a loud noise when releasing the brake. seems easiest to replicate if i get up to 15/20, brake kinda hard, then release; i don't have to be completely off, maybe 50% then i will hear a *plunk* - what could this be? is it something to worry about?