Here is another possible cause for pulling to one side when braking:
I had that same problem, before I replaced the Oakie bushing of the torque tube to U-joint connection.
Trans oil ran down the torque tube and found its way into my left rear drum.
Although I thought the front brakes do most of the work, breaking power was almost reduced by half and the truck was pulling to the right when breaking.
Brake pads are useless once they have been soaked in any kind of grease, oil or lube and MUST be replaced. Soaking in cleaning solution is no good.
Major parts suppliers give life-time warranty on brake pads and you can replace them as often as you like for free.
Brakes ARE the MOST important element of any moving vehicle ...
