Brake pedal was getting mushy ( yeah I know, bad year for strong brakes) Ordered a set of Delco rear pads and had some DOT4 fluid . Put them on in the sweltering heat this afternoon, flushed the fluid. Much better, got rid of a lot of fade and yes the rear pads were original and right at the backing plate. Coming up this next weekend, front calipers , rotors etc from the 07 Tahoe, that should step it up a bit more