I have the same problem. Have turned the drums and the brakes look good. Unhooked ABS just to see if it was impacting the braking. No change. I'm stumped too!

 

Bad rear wheel bearings are to blame a lot of the time for a "hop"....or shudder under light braking. If you do replace the outer bearings, be sure the axle is not worn under the bearing area. If it is....get a new axle. They make a repair sleeve for it.....I tried it and it was a total waste of $50.00 bucks.

 

just a suggestion here, may want to check your tranny and motor mounts

 

I have a 2003 f150 2wd with the same wheel hop problem. changed rotors and pads 3 times emg brake shoes and cable new shocks new rear axle and bearing need ideas thanks

 

My final answer to my cold braking issue was 3 of the 5 lug nuts were over tightened and distorted the hub and the disc on the left front.
As soon at the disc got hot from brake use the problem nearly went way by taking the 'wave' out of the disc only to return again when it cooled.