I took about an hour today and disassembled the brakes on my 2000 2X4 400 Scrambler and inspected them. I found no apperant problem but did notice that the pads were put into the caliper without any type of silencer. I cleaned the pads and sanded them down very slightly with some 180 grit on a flat surface, cleaned them again and put some automotive "disc brake silencer" on the back of the pads. I reassembled everything and test rode it. No more squealing or grinding!!!!
I did have to break the pads back in though, so if you do as I did, don't go tearing off as the brakes won't work as well 'till you get them good and hot the first time.
Total Time: about an Hour and a Half
Total Cost: about $ 5.00
I hope this helps you guys....

 

Good idea Nemo, I was planning on doing the same thing to the brakes on my '99 Scrambler. They are pretty squeaky and have been since I got it the first of Feb.
Matt '99 Scr400 '00 Trailblazer