2002 Venture Caliper Pin Bushing

2002 Chevy Venture Van: Just replaced front brake discs and pads. The top(leading) caliper pin bolt has a bushing at the end. The bottom(trailing) caliper pin bolt is solid. I made sure to replace them in the same positions. Does anyone know the reason for the bushing on the top pin? I thought it may be because the caliper can be hinged up to expose the pads in the bracket?