I removed the pads from the passenger side brake. The disk spun free without the pads, like a new bicycle wheel. I found the lower caliper guide pin pretty stiff. Top guide pin was fine. I also found that both pad shims were out of place. The outer shim had dropped against the hub, and was ground half away. I also found the pads themselves to be nearly new, thickness within 1 mm of a new pad I happened to have on hand.

On the driver side, the lower guide pin was a little stiff, not as much as on passenger side. The outer pad shim was also out of place, also ground half away from dragging on hub. Inner shim was in place.

The outer pad itself was hard to remove from caliper. Had to smack it with a screwdriver handle.

Only an hour of light left (repairs being done outside) so I skipped cleaning the lower guide pin on driver side. Having no spare shims on hand, I assembled brakes without shims. I did use CRC "pink" brake pad goop.

After assembly I pumped brakes hard. Both wheels would spin with one hand now, and coast about 1 revolution after a hard spin. Much better than before. Test driving showed the (very obvious) surge/dip that was happening before was gone. The car was riding much smoother. Tried a 50 MPH hard/panic stop, car stopped straight. Only very slight shudder, which I attribute to less than perfect rotors, or maybe marginal radius rod bushings.

Conclusion: The stuck guide pin may have contributed some. I suspect a significant contributor was the shims out of place, causing the pads to bind in the caliper, and not float as they should. The shims dragging on the hub may have made it hard to turn by hand, but probably did not have sufficient friction to be effecting the mass of the car in motion.

With things cleaned up, freed up,and in alignment, it seems to be okay now. Time will tell.

Thanks for directing me to these maintenence level items first.
It was a terrific reminder of the mantra I've seen here before, "Check the simple things first". But more important, thanks for sharing your knowledge of what these "simple things" are.

Question: How important are those shims that I left out?
Are they only for anti-squeal, hence if I have no squeel I don't need them?
Or do they play some more significant role in pad alignment, or something?

-rcf

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-rcf