need help with brake diagnosis

what a coincidence then.

update. took all four wheels off. fronts are solid. pads are seated. rears are seated. but there seems to be the slightest play in the caliper. so i could see the pressure of the caliper having anough momentum before contact with the rotor to cause the noise. but all bolts are tight. every one. so i am stumped. no leaks, and only the rears seem to be loose. stumped. this would be so much better if i werent on blacktop in the middle of southie boston in 95 degree heat. damn