I'm located in Melbourne, Australia and my 64 sedan de ville is stuck in the garage due to failed mechanical fuel pump. The first after market mechanical fuel pump lasted a few years before it failed & left me stranded 5 hours from home. A hire car and tow got us home. On inspection, I noticed a valve not seated within the housing. I was optimistic, pressed it into place and assumed the pump was good to go. But alas, no. From what I can now determine, the diaphragm pushrod appears to be jumping off the pumping actuating lever. I recently replaced the pump with yet another similar after market mechanical fuel pump which lasted a few hundred miles before failing. I disassembled the second pump to find both valves in place but again the diaphragm pushrod has jumped off the actuating lever. Can anyone shed some light on my problem? I think my only option now is an electric fuel pump.