I just did the first fuel filter change on my truck since I've had it. The old fuel filter was black. I know on my last truck (99.5 F350 PSD) they said if the fuel filter was black it meant problems with leaky injectors or something like that and it was never black or even discolored. Is this something I need to be worried about?
Thanks,
Darrell

 

They always get black after use...............

 

Nah. Leaky injectors causing a black fuel filter sounds like a line of Dealership B.S. being as how they are down stream and can't affect the filter. Mine's always been somewhere between battleship gray and next to black when I change it.

 

No way that leaking injectors could cause a dark color on the fuel filter. Sheesh. You would think that the dealer would tell the truth.

 

I've always been told the black is algae or bacteria. It is coming from your service station or your tank. Use an algaecide like Power Service Silver to clean your tank and kill the "fuel bugs". Install a fuel pressure guage post filter to monitor the filter and it's performance. Contact your service station and tell them you are having algae problems. They can add an algaecide to their tank.

http://www.baldwinfilter.com/engineer/94_14.html

Fungus and Bacteria -- these microorganisms live in water and feed on the hydrocarbons found in fuel. Called Humbugs for short, these active and multiplying colonies will spread through a fuel system and quickly plug a fuel filter. The fuel filter will have a slime coating over the entire surface of the media. Bacteria may be any color, but is usually black, green, or brown. Draining the fuel system will reduce microbial activity, but it will not eliminate it. The only way to eliminate microbial growth once it has started, is to clean and treat the system with a biocide.

 

Not in our lifetime.

 

Not mine. I use Power Service to kill the algae. Mine are gray.

 

The black filters your seeing are coated with a naturally occuring substance in diesel fuel called Asphaltene (Asphalt). It does no harm and Cummins sells a product called "Ashpaltene Conditioner" mainly geared towards big rigs. I have only seen algae on marine diesels. It smells musty and feels slimey. Algae needs water to thrive and grows in the boundry between diesel and water.

 

The black color spoken about in the original post maybe from leaky injector o-rings from a PSD. They use high pressure oil to actuate the injector, and the oil can get into the fuel if the o-rings are bad.

Rusty