I have a 1990 Ford F350 XLT Lariet 2wd, my brakes keep locking up, I have reaplaced the master cylinder, rear wheel cylinders, wheel hardware, brake shoes and rubber brake line at rear of vehicle, one wheel keeps locking up and I don't know what else to do. Please help me if you have an answer.

 

And which wheel might that be? the rear drum brake units each have a self adjust mechanism (top rear part of brake)that allows adjustment by applying the parking break while driving in reverse. I don't know what effect one side being set at a more advanced setting compared to the other would result in. I think failure to compleatly remove air in system would do it. Was this the reason for the brake work or the result of? Also what have the brake & ABS warning lights been doing all this? There is a terminal under dash/driver side that provides ABS sys error codes via similar paperclip method used for ECC code retrievals.

 

Any chance your parking brake cable is stuck?

 

and if that fails - turn the drums