Dmundell, I got a right brake pull on my truck out of the clear blue at about 50K miles, I had never had it to any degree before that. Long story short it went in a couple of times having all of the brake lines, hoses, calipers and both knucles replaced. It would yank you off the road if you hit the brakes hard and were not ready for the pull about half the time, the other half it would stop straight. It went back in and was a lot better when I got it back that time. It always pulled but it was not bad, if you let go of the wheel it would wreck you, but was not a huge fight to keep on the road. Shortly after that I found the spacers, I pulled them out and it was better, but pulled hard once in a while again. I had been religously lubing the caliper pins all along with no apparent effect.
I finally pulled the calipers out and polished the slide surfaces of the calipers and knuckles with a fine file, I got about 60% of the surface smooth as can be. There are some deep machining marks on them, and if you file them out you will likely remove enough material to get a torsional bind. Just knock them down where the surface is smooth overall and the high spots are gone. Then reassemble with some good brake lube on the slide surfaces. You will want to polish any burrs off the pins as well when you have it apart. My brake pull is now history, I clean and put new lube on about every 10K miles to keep the grit from letting it bind.
All of the "repairs" were done to mine under warranty, so I gave them a shot at getting it right. The dealers (2 of them) failed miserably, I fixed it in an hour in my driveway after looking at it long enough to see what the problem was. I bought the warranty so I try to use it, but lately it isn't worth a lot.
Give this a shot, I think it will work for you too. Let me know if you have any questions.