Join Date: Jun 2008
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I posted this in another thread. It is relevant to this discussion:
Water is present in diesel fuel at the refineries and is removed by chemical processes and coalescing filters. ULS diesel has compounded the problem.
Here is a quote from one source on the issue:
"Ultralow sulfur diesel fuel will be mandated for use in
on and off road vehicles in 2007. When low sulfur
diesel was introduced in Europe and California for onhighway
vehicles there was widespread damage to
injection systems, including, excessive wear and
failure. New media was needed with increased filter
efficiency, water removal and life to meet the demands
of the new fuel.
The addition of biodiesel to the fuel can cause
additional water separation and wear problems.
Dissolved water is more prevalent in biodiesel and the
presence of water can cause reversion of biodiesel to
fatty acid increasing filter plugging. Biodiesel fuel has
higher acid numbers than traditional petroleum based
diesel. The acid number for biodiesel measures free
fatty acids or degradation by-products not found in
petrodiesel. Increased recycle temperatures in new fuel
system designs may accelerate fuel degradation which
could result in high acid values and increased filter
There are two classes of the problem 1) A large amount of water that gets put into a fuel tank from a tank at a service station and 2) micro droplets that are in the fuel at every fuel station (delivered that way from the refinery). The best way micro droplets of water can be removed from diesel fuel is with a coalescer filter. The Ford horizontal filter under the driver side of the truck is a paper element so it is not a true coalescer filter. The filters work by stopping small drops on the filter element and having them collide with additional drops combining them into larger drops, where they eventually get large enough to drop to the bottom of the filter. So if you get a couple gallons of water pumped into your tank from a service station and a large charge of that makes it to your Ford filter, it is going to go right through because that is not these filters work. Suspended water shows up as a haze in the fuel - you cannot actually see drops.
The only "improved solution" I could find is add an additional coalescer filter ahead of the Ford filter, preferably something better than the Ford filter. Water separator filters are made by Racor, Fleetguard, and a number of others. Particle size must be selected as part of the selection criteria.
By the way, some have experienced a wax buildup in their filters which eventually blocks the filter. Here is an excerpt from BP on what causes the wax.
Under cold conditions wax can be seen as a light yellow suspension in the fuel. When the fuel is cooled below the temperature at which the wax comes out of solution (cloud point) it can block filters by forming a yellow waxy deposit. This is a result of using the incorrect fuel for the season or region, eg. using summer grade ADF in winter or bringing an ADF from warmer areas to a colder area during winter. To help prevent waxing problems you should always ensure that all fuel is changed over to fresh fuel There is a lead time in the distribution of the fuel to ensure that all fuel available is winter grade for the cold period.
TDW - Purchased July, 2008
2008 Black F350 Lariat
DRW 4x4 Crewcab Long Bed Job 3
Navigation System with Audiophile
3.73 Read End
13k LB Carriage Cameo 5th Wheel