GuiGuru

You saying it does not make the sound while the brake is applied made me think of something else. I know you replaced the pads since the noise started. However, did you replace the anti-rattle clips or inspect the exciting clips to make sure they haven't broken? Each front caliper has 5 clips in it, if one or more are broken/missing those pads can cause a serious racket.

dave1123

One thing I can think of is worn caliper mounting brackets. The pads fit into and are held in place by these brackets. If the slide surfaces are worn, they allow the pads to rattle. If they have grooves worn in them, replace them. You can hard surface weld them, but for the cost, just replace them. On the WJs they are just bolted on. On the XJs and ZJs, they are part of the steering knuckle.

My WJ has this problem when I changed to ceramic pads. The mounting brackets were replaced at that time as well, but the new pads rattled anyway. After putting up with it for about 4 months, I went back to semi-metalic pads. No more rattle. On these dual-piston calipers, there are no clips that secure the outer pads, only a stabilizer clip for the 2 sections of the caliper. (Teves calipers) I was going to try that "blue membrane" stuff, but the outer pad goes onto the slide before the caliper goes on, and it kept getting wiped off on assembly.