The second retaining post where the tail of the small spring pushes against is missing on 2 of my 3 portafilters, evidently that is a common failure but no problem, when reassembled, the tail of the spring pushes against the lower housing and still functions as good (actually better) than ever, the value of a good cleaning every once in a while can not be overrated. I have cleaned all my portafilters and they operate better, the pressure build up and release is back to proper operation. I have also disassembled and cleaned one of my pumps which was acting sluggish, just a cleaning and a much improved operations, there is a site which shows you how to disassemble the pump also, just search for it.