I've done some light maintenance on cheap side caliper systems and I've run into this problem on a few older bikes.
When the the brakes are applied, the pads barely move at all. I've adjusted the brakes so the pads are closer, but they still don't come far enough. They are also rather difficult to push. This only seems to occur on the rear brakes, presumably because they're used the most (at least by these bikers).
Do I need to just get new (better) brake systems or is there some way to fix this?