It is very difficult to tell exactly where the pump is leaking, but from the image below it looks like it is between two "plates" that make up the body of the pump.
Before I hooked everything up I made sure all screws were tights and things were in place. Including the 4 silver screws on the bottom of the pump. I believe they were tight, but I may have made them a tiny tighter when going over everything. I can't see why anything would leak, these aren't even pressurized systems. The water just flows through. Did you try contacting Syscooling or Bitmain for a replacement? I emailed FrozenCPU asking them what would be a good backup/alternative to the pump we use here.