I love my Silca Super Pista pump. It recently stopped holding pressure so I took it apart and discovered the leather plunger cup had deformed on one side. Also the original plastic washer had cracked, probably causing the failure . I got a new metal washer the same size from my toolbox , threaded on the new leather plunger, greased it up, bolted it back on and I'm back in business. I love things that are rebuildable and come out as good as new!