Fuel Filter Pressure Gauge
Written by Rickdatech
Since Biodiesel is such a good solvent, any trash that gets in the tank will eventually end up in the fuel filter. It can be from old gunk from petrol diesel usage, or from when we buy diesel at the pump for winter blending. If it catches us off guard, we can end up changing out a fuel filter on the side of the highway, in the snow. Some late model vehicles have fuel filter sensors that will let you know, one way or the other, if your filter is starting to clog. You can ask your diesel mechanic if your specific vehicle has a fuel filter sensor and how the car will notify you of an impending clogged filter.
If your diesel doesn't have a sensor, adding a fuel filter gauge can be a great help in identifying a fuel filter that is reaching its limits. This one from Zinga, was designed for hydraulic filters, but seems to work just fine for biodiesel filters. These are vacuum gauges and are installed in the fuel line on the suction side of the IP. As the filter clogs, the IP is forced to pull a vacuum on the section of line between the fuel filter and the IP. having a lift pump before or after the filter does not change the readings any. Although a lift pump does effectively extend the functional life of the filter.
Racor sells a filter and gauge combination that does the same thing. Racor recommends replacing the filter when the gauge reads 7-11 inches of vacuum. There are also a number of diesel parts houses that offer a fuel filter gauge kit.