My truck is a 07 Silverado 2500 hd 6.0L 4X4 crew cab with 142K mlies on it. so when i'm driving around everything is smooth and great until i hit the brakes. at first when the brakes are cool it is smooth but as the brakes heat up the front driver side wheel sounds like its going to fall off. it makes kind of a slapping sound and feels like it is going up and down. i have replaced the tie rods inner and outer, the pitman arm. idler arm. and all new rotors brake pads and even the caliper and new shocks i have had it at different shops and nobody seems to know what it is. Could it be bad swaybar bushings? i haven't checked them yet. any advice or suggestions would be greatly appreciated.