2nd Gen Non-Engine/Transmission brake judder

[gustapus]

Got an '01 with rear disc brakes and 30k on the odometer. I take real good care of this vehicle. Just recently, when stopping, I get what only can be described as a "judder" from the truck, particulary when slow-speed stopping. First 1-2 "cold" stops in the morning are fine. Don't feel any pulsating in the pedal, nor any kind of steering-wheel feed-back. Running OEM-size Radial A/Ts with 55 psi front/rear. Run empty most of the time, weekends with maybe 600-700 lbs, total. Problem shows up empty or loaded. Problem seemed to start when I experimented with putting the tire pressure up to 57 psi front/rear, then went up to 5000' altitude, which put the tire pressure up to 62 psi. Probably unreleated. Going to rotate the tires this weekend and pull tha calipers for a look-see. Would appreciate any thoughts on where to look - track bar?, or warped rotors? or put the rears at 10 psi less than fronts (45 psi)?, or... ... ... .