Fuel/Water Separator turning black

Discussion in 'Trucks [ Eighteen Wheelers ]' started by TruckkinItUp, Dec 15, 2021.

  1. Goodysnap

    Goodysnap Road Train Member

    2,910
    6,770
    Jul 12, 2017
    0
    You didn’t answer my question. Is the Davco filter actually filling to the top? Are you getting fault codes for fuel pressure and is it actually plugging?

    If you are getting particles from the separator drain they are being put into the tank. Or at least show us what it is?
     
    TruckkinItUp Thanks this.
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. TruckkinItUp

    TruckkinItUp Bobtail Member

    17
    3
    Jan 8, 2020
    0

    Thanks for trying to help it's very much appreciated man..


    As far as the level in the globe.. sometimes the level is flush with the housing or bowl and the filter is already black or stained. The fuel mileage will drop sometimes right there the level hasn't even come up an 1/8 ..

    Sometimes the level will shoot straight up to half of the globe so it varies..
    As soon as that filter starts to turn colors fuel mileage goes to s***.


    I'm not getting anything fuel related as far as warning lights on the dash..

    Plugging I don't know anything about...


    I will also try to get pictures as soon as I can of the flakes or sediment whatever it is and bring them back here..

    Your time and effort trying to help solve this problem is greatly appreciated.




    One thing of note is that the fuel lines going to the davco bowl get warm and I was told by an old trucker that those aren't supposed to be getting warm.. I mentioned this to the shop that I used and they can't wrap their head around it...
     
  4. marmonman

    marmonman Road Train Member

    1,400
    2,661
    Dec 14, 2009
    central illinois
    0
    If the fuel in the tank is clear and shows no signs of sediment i think I would be looking at my hoses from tank to filter . They may be breaking down on the inside . That seems to be the only other option to me . Just my two cents .
     
    TruckkinItUp Thanks this.
  5. Deezl Smoke

    Deezl Smoke Light Load Member

    229
    88
    Feb 12, 2011
    Hillsboro Oregon
    0
    I used to run fleetguard until I started having issues with hydraulic filter quality, then air filters showed up bent and with paper element pleats messed up and stuck together.
    Do you have coolant based fuel heaters in either tank?
    If you take a rag and wipe aluminum, the rag turns black or dark graphite color. Flip the rag and wipe down a rubber hose and you cant tell which side is which.
    You mention only inspecting one fuel tank? Before you spend another dollar, I would remove the screen and inspect the other tank. Never assume anything. Verify before proceeding.
    Then, since this is costing you money to keep running anyway. Go away from the discounted fuel and run a few fill ups from another source on new filters.
    Eliminate the fuel source before continuing to spend money on parts. Verify the condition of both tanks with visual inspection before more parts.
     
    TruckkinItUp Thanks this.
  6. Deezl Smoke

    Deezl Smoke Light Load Member

    229
    88
    Feb 12, 2011
    Hillsboro Oregon
    0
    I know you're running a Cummins, but this video came up and thought it may be relevant.
    Youtube video of black fuel.
    Even though you mentioned injectors, the video explains bad remanufacture of injectors.
     
  7. kwcam

    kwcam Light Load Member

    173
    128
    Dec 29, 2012
    at the shop
    0
    When fuel gets hot it will turn black/dark due to something called ashphaltenes (spelling ?) separating out of the fuel.
    Does the Davco have a heating element in it ? if so unplug it for a while, might be stuck on. Does the fuel in the tanks turn dark before you refuel ? some of the older 870 and 871 engines would turn the fuel black from running so hot.
     
    gentleroger and Goodysnap Thank this.
  8. Goodysnap

    Goodysnap Road Train Member

    2,910
    6,770
    Jul 12, 2017
    0
    You are correct. This condition according to Cummins also had no affect on runability or plugging of filters. I don’t think tank or fuel heaters would get the fuel hot enough to cause this. Mechanical injectors is what cause the excess heat to my knowledge.
     
    gentleroger Thanks this.
  9. jamespmack

    jamespmack Road Train Member

    17,081
    189,957
    Mar 25, 2014
    OH
    0
    If diesel fuel exceeds 140° recirculation temperature. Asphaltene begins to appear.
     
    little cat 500 and gentleroger Thank this.
  10. sirhwy

    sirhwy Medium Load Member

    344
    681
    Sep 1, 2011
    Central Iowa
    0
    Nobody has mentioned fungus. Does your fuel smell like something dead? If so, there’s some stuff you can dump in there to clear it up.
     
  11. d281833

    d281833 Heavy Load Member

    879
    903
    May 15, 2012
    0
    It's in his post-

    -fuel tanks have always checked clear of algae but still ran algae killer in them
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  • Draft saved Draft deleted