Hi, I hope someone can shed some light on this for me. I have a 2013 Yukon XL 1500 with 203,000 miles. It vibrates when driving and gets worse when braking. It doesn't do it all the time while driving but always when braking. I took it to the dealer and they said it needed new rotors and pads so I replaced both on front and rear. It was great for about 2 weeks and today out of nowhere it started doing the same thing.