I noticed a fuel leak from under my 280sl and thought that it was coming from a cracked fuel line. I replaced all lines; the leaking continued and actually worsened. After reading the posts on the site, I decided to replace the O-rings. In the disassembly process, I needed to remove the 3 screws holding the top section to the pump section. I noticed that there are no threads in the pump section for the 3 screws in the top section to attach to. How is this connection made secure? Has something connecting the 2 sections come loose over the years and fallen off the vehicle? I consider myself lucky that the 2 sections hadn't separated earlier and left me stranded!