Last fall the rear discs were operating against the outside of the rotor only - both sides of the truck. This at about 16,000 miles. GM did replace everything - rotors, calipers, slides, pads under warranty.
Now at 27,000 miles, the fronts are doing the same thing - I thought a wheel bearing was bad, took it in, no, it's the brakes, calipers are froze, operating against the outside of the rotors - girl service writer says there are rust problems in the north - then I told her this truck spends it's winters in Florida, she needs to come up with a better one than that.
They charged me $73.00 to tell me I have bad brakes. I am going to go to aftermarket stuff, GM junk would be the last thing I put back on.
Needless to say, I have lost any faith I had in GM - was treated poorly by the dealership. Had a sticker on my rear view mirror when I picked up the truck - says" we have given your vehicle a courtesy wash today!" Damn truck was the same as when I had brought it there.
Hope I get to fill out a CSI on this one -

 

This is a very common problem with factory GM truck rotors. Most likely there is nothing wrong with the calipers. Replace the rotor with a good quality aftermarket part and you will not have a issue again.

 

check out summit racing they have pretty good packages.