I was not expecting the fuel filter to look like this...

Yes, I am a first time diesel truck owner. The 2005 Dodge Ram 4X4 with an 8 foot bed is possibly more than required, but the snow in front of the house this morning reminds me why I have the truck.  It currently has just over 310.000 miles and yes it is showing its age but is willing.

Last weekend it did almost 800 miles of work with a load and at 15 MPG I am very happy.  Before the trip I did have the three gallons of oil changed.  I understand the color of the oil, that I get.  I changed the fuel filter, getting to purchase a new tool is my introduction to yet again another vehicle in my fleet.

I am once again wondering how a manufacture decides the size the fasteners of their vehicles.  This turns out to be a 29 mm, 3/8 drive.  The color of the filter in the next shot got my attention.

No, I have no idea how old or how many miles the old filter has been in the truck.  I did clean out the filter housing before I dropped in the new filter and it was not as filthy as you might expect given the condition of the old filter.  I am going to change the filter at 15,000 miles to get an idea of what to expect going forward.  

The learning curve of this thing is just getting started.  Next is driving in the snow! 

Yikes!

My general understanding is diesel fuel filters need more regular replacement. The service interval for my 2003 VW TDI was every 20K miles.  Sold at 329K miles, I changed that filter a lot.  And that engine was relatively low pressure. I understand the newer high-pressure injection systems are even more sensitive to dirty fuel. 

Biologicals will grow in diesel. It is common to have microbes growing in a tank that isn't used often. 

At a guess, that filter is full of it. I'd probably run some biocide through it just to be safe and only fill up at busy stations that fill their diesel tanks often. 

Edit to say, I would short change the next filter to make sure you aren't starving the pump. That will destroy the injection pump in short order. They are lubed and cooled by the fuel. 

Interesting, thanks Toyman. I haven't been towing as much in the past few years so the Big Diesel Pickup isn't racking up the miles the way it was. I might swap out the fuel filter just to be sure and see what it looks like.

When I got the Big Diesel Pickup, I was not expecting it to have higher regular maintenance needs than the cars - I expected the opposite. But of course it's working a lot harder so of course it goes through filters (air, oil and fuel) much more quickly. I keep a spare fuel filter in the truck just in case.

I have a Ford 6.0 diesel and change the 2 fuel filters every 5k miles. The filters look just like the one in the image in the first post.

If the truck is running a recirc system through the EGR area, its also possible the fuel is returning to the tank extremely hot, causing the asphaltines to clump up. Fuel that is right on the verge of usability will react faster than fuel on the other end of the spectrum. Someyimes installing a cooling loop helps with that. 

Additional fuel filtration is pretty highly recommended on the common rail trucks.  You can get there with a FASS or AirDog lift pump, or you put an additional filter under the hood.  The injectors on these engines are expensive, and the factory fuel filter isn't great.  I think the finest OEM style filter is around 10 microns.  With a spin on filter, you can get down to 2 microns.