brakes feel like they are sticking

my brakes feel as they are sticking sometimes. some of the time when driving the brake pedal feels as if you barely have to press on it before it starts braking and when they feel like they arent dragging the pedal takes about an inch or two before it starts to brake. sometimes when it is dragging it will make the car vibrate badly at higher speeds. I replaced both front calipers, brake pads, and one of the front brake lines i also checked for kinks in the metal lines and everything seems to look good.