Hello John, this sounds very much like "Diesel Pest". While this gets much attention in a warmer climate like the Med, and even in the North Sea, hardly anybody mentions this phenomenon in the USA or Carribean.
It ist caused by bacteria which live on diesel
using traces of water
. These bacteria produce a jelly-like substance which will clog up completely Your piping and hoses, even before anything is reaching Your filters. So Your filter is looking normal, though no diesel
is passing through.
To cure this problem You will have to clean not only Your tank, but also all tubing. Remove all water
out of the system. Use "Grotamar" as additive to your fuel.
This should always be used in order to prevent future problems.