Tweaked 5300

Hello everyone, I hope someone can give me some advised about this noise im hearing from the front of the truck when braking kinda fast, at first i thought is was the i-shaft making noise and then i got replaced under warranty anyway and next the noise is still there and still at the dealership with 3 techs under my truck and they said they have no idea what the noise is but you can hear it when doing gas then brake method quickly the clunk noise is very auditable with the window down and can feel it in the steering wheel, so yesterday i took the truck to my dads since he was a tech at one time and has every tool i believe, and jacked it up and took the front left wheel off and it seems i can hear the noise there the most and then i was able to move the caliper very freely and it made this clunking noise that i believe thats the problem and then i took the front right wheel as well and checked that caliper and it moved freely just as the other and all bolts were still tighten on both calipers, but it shocked me about how freely both calipers were loose or very free to move within the caliper bracket!
Just wondering, on GM trucks is the front brake calipers suppose to be like this? since front and rear brakes have been replaced under warranty about 20,000 miles and pads have about 50% left and now i have 58,000 miles on the truck. All i know this noise is driving me crazy and any advice would be great about this and also i have a annoying squeak from the left front as well and found out the the pads the ride on the anti rattle clips is causing that noise and will fix it soon.

Thanks to everyone out there

Grumpy5.3

iTrader: (14)

are you 2wd??? if you are try tightening your crossmember that goes under the oil pan. that is a common problem. just get a 1/2 inch pull bar, 18mm socket and a 18mm wrench. pull til they are good and tight