In order to provide clean fuel it is run through two filters. A (relatively) coarse primary and then a fine secondary. The latter is on the engine, in my case no longer a canister with an element in it, but a spin on modern filter. The primary is a RACOR. Large, robust and pretty much the industry standard. There’s a gauge on top which will show an increased vacuum when the filter clogs and the engine is sucking too hard to get fuel….
Under the lid is a disposable filter element, and at the bottom is a sediment bowl, translucent, so you gan see the large chunks and, should it find it’s way into your fuel, water. There’s a pet cock to drain the crud and/or water out. Mine looked like this: (after draining out the fuel.)
So I took it apart and cleaned it up. Here is the “operating theater” in the hall way between the engine rooms. The black tub is a Wallymart oil change tub. It’s a catch basin with a drain into a can. Holds the oil (or in my case fuel) and the basin makes an excellent parts cleaning sink. Drain the filters into small tubs and pour into basin. Save some for cleaning things. At the end drain it all, close it up and carry it to a place of “responsible disposal”……
Last but not least diesels do NOT like air in their fuel supply and can’t get rid of it themselves. So after draining and cleaning of the filter you have to put in a new cartridge and fill it with clean diesel. Messy. But, someone prior to me put in a small “priming pump” yeah! Flip the switch and watch it fill up, all the way to the top. Put the lid back on and it started right away! Behind it, the big red thing, is a modern style spin on oil filter. Also a later improvement on the original messy canister with element in it.