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ATF in fuel filter

Discussion in '6.9L IH & 7.3L IDI Diesels' started by chris142, Sep 14, 2020.

  1. chris142

    chris142 Full Access Member

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    I keep reading about doing this to perk up a tired injection pump. Any particular brand or type of ATF?

    What is the proper procedure?
     
  2. Scotty4

    Scotty4 Supporting Member Supporting Member

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    Fill a new filter with atf and install. Any type will do it. I used the left overs from filling my transfer case. Start the truck and let run until you hear a difference in the engine and then shut it off. Let sit over night or a solid 24 or so hours. Take it out for a spin and drive it hard for a little while.

    My engine smoothed out quit a bit after doing it.
     
  3. chris142

    chris142 Full Access Member

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    Thanks. I have Dex3 from Pep boys for my transfercase too haha.
     
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  4. chris142

    chris142 Full Access Member

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    Ok I dun did it. I can drive it tomorrow or the next day as I have 2 cars.little rough getting him started. Died a couple of times them ran bad a few min.
     
  5. Cubey

    Cubey Full timer RVer

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    I just removed the not-very-old filter, with a rubber strap wrench so it wouldn't damage it, dumped the diesel back into the tank with a funnel, then filled it with ATF with a bit on the seal, and put it back on. I did so on my RV a year ago. No leaking from the gasket, so no real need to replace it unless your filter is due for a change.
     
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  6. chris142

    chris142 Full Access Member

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    I bought a case of filters years ago. They were cheap on fleabay. I would rather use a new one vs possibly getting contaminants on the clean side of the filter then pumping the contaminants onto the pump.
     
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  7. Cubey

    Cubey Full timer RVer

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    I can't imagine it being any more of a risk with a used filter than with a new. A new filter has just as much chance when you're pouring in the fluid. I have the genuine MC filter on the RV.
     
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  8. The_Josh_Bear

    The_Josh_Bear Full Access Member

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    Since we are taking about it:

    Pour whatever cleaner you're gonna use into the small holes surrounding the large center hole only-- don't pour anything into the large center hole. That is straight to the IP and unfiltered. Pouring through the outer holes makes sure you go through the fiter media before IP ingestion.
     
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  9. Fredrickson

    Fredrickson Registered User

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    At the sake of sounding a bit dense, and too detail oriented..

    Is it better to have the engine 'warm-ish' when the ATF is passed through it to the injectors before the overnight soak? (ie, have the engine still warm when filling the fuel filter)

    The next day, when driving it hard.. I am a good 15 minute drive (slow speed, local streets) before I can get to a highway, and open it up.. BUT i have some fairly steep long hills close by. Is the point to have high flow through the injectors to blast off any loose deposits and crud?
    Would driving hard up steep hills serve the same purpose as a highway run?
    (or would dropping the transmission into 2nd accomplish the same goal?)


    (My fear is the engine won't well enough/long enough to clear the ATF and get to straight diesel leaving me stalled on the side of the road, on a steep hill.. How bad does the engine run with the ATF?)
     
  10. Cubey

    Cubey Full timer RVer

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    IDIs can run on pure ATF. But if you are that worried, you could remove the fuel filter again, dump it out and refill it with diesel before driving it.

    I say just put it in neutral and give it a little throttle for a couple of minutes to help push out the ATF faster. Even if it's not all gone, it'll be diluted enough that it shoudn't run any differently.
     
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  11. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    The biggest advantage that I could see here would be that the engine is already warm and should start easier after the filter is reinstalled. From my experience with changing fuel filters, it just seems to recover from the trapped air better. Sometimes, when the engine is cold, it will stall out from the air and then you have the "fun" of bleeding and repriming the fuel system. A warm engine just didn't seem to have that issue.
     
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  12. chris142

    chris142 Full Access Member

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    Ok. It sat all monday night,all of Tuesday then all tuesday night. In an hour or so I will attempt to start it and drive to work.
     
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  13. Fredrickson

    Fredrickson Registered User

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  14. chris142

    chris142 Full Access Member

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    Drove it today. Seems to smoke much less. Nothing else seems different.
     
  15. Cubey

    Cubey Full timer RVer

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    Wait and see if it helps your MPG
     

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