Hi, I was not sure if this was the area to post this but here goes. I have a 1999 Tahoe with 10 inch drum brakes on the rear. It is a 2 wheel drive 4 door. The continuing problem have is that the rear drum brakes keep unadjusting themselves. I have had them adjusted by a couple of different shops but it keeps happening. The hardware has been replaced, wheel cylinders and shoes have all bee replaced but it keeps happening. The brakes work fine for a few weeks and then they slowly get worse, even the parking brake pedal is tight at first but ends up almost all of the way done when you press it after a few weeks. I can't figure it out. Can someone shed any light on this. I would appreciate any help with this.