rsaltaresjr
Registered User
I personally have seen the damage water can inflict on injection systems, especially on common rail systems. The pleats on a standard duty filter are treated chemically to be hydrophobic or basically water repelling, usually with silicon. Dispersed water in fuel will form droplets on the pleats and the specific gravity of the water being heavier than the fuel means they will fall to the bottom of the bowl. If the accumulated water is not drained it absolutely will pass through the filter pleats and be introduced into the injector pump and injectors. A water blocking filter uses media that will actually absorb and trap water until restriction develops and ceases flow unless bypassed. I've only ever seen these type filters used on fuel dispensing systems such as diesel transfer pumps. All fuel stored in mass has some amount of water. Its impossible for it not to. If engine mounted diesel filters were of this water absorbing/blocking type you'd be changing them every 10 hours of run time. The problem here is not water building to a point that it restricts the flow of fuel. The filter/water separator simply doesn't function this way.
