So here is the deal. My roomate and I go to put new pads on the GT at his mom's house. Front passenger side goes without a hitch. Rear passenger and driver side, not so much.
The guide pins for the rear calipers had become one with the caliper mount. Somehow, the grease turned to some sort of clay and allowed the pins to rust in place. After soaking for 30 min in PJ's penetrating liquid they still would not budge.
I managed to get one out and the grease looked like someone had lubed it up with mud. So now I have to replace 2 mounting brackets and 4 guide pins.
I go to the stealership and they asked what kind of car I had. I politely replied 2000 Mustang GT. and the guy interrupted before I could tell him what I needed and said "Rear caliper mounts and guide pins right?"
Apparently this is such a problem the 2 dealerships I had to go to, they all had the part number memorized for the caliper mounts and guide pins.
Dealer part only, you wont be able to pick them up at an Napa or AutoZone. 48 bucks a piece + tax. And this does not include the guide pins or dust boots. And the guide pin kit does not include the dust boots either.
So if you have an 8.8 with disk brakes. Check your guide pins now. and even if they are fine, clean the pins and holes they go into and grease the hell out of them. Also check the rubber dust boot, they are 5 bucks A PIECE so be careful not to break them.