06 CP3 fuel leak

Discussion in '5.9L Engine and Transmissions (2003-2007)' started by CRHardie, May 1, 2021.

  1. CRHardie

    My 06 has 108000 miles on it now. Was servicing it the other night and noticed a fuel leak coming from the CP3. I can’t determine where on the pump it’s coming from though. Maybe this is the cause of my extended crank time after it sits for a few days. Any suggestions?
    Thank you all
     
    CRHardie , May 1, 2021
    #1

  2. cerberusiam Staff Member

    CP-3's frequently leak, they leak worse with age due to the o-rings in the body aging. Do you see a large puddle of ufel under the truck after it sits for a few days? Usually the CP-3 only leaked when they were warmed, but, if you are seeing a fuel spot then it is worse than normal.
     
    cerberusiam , May 1, 2021
    #2
    Darkbloodmon likes this.

  3. CRHardie

    I see a damp spot on the garage floor but no actual puddles of fuel. I shave a company service truck so this one may sit a week at a time without running. There are drips of fuel hanging off the wire harness for crank sensor and fan clutch. Guess I never figured I would have to replace this Bosch pump. We get 20,000 hours or more on the Denso pumps on Deere engines at work.
     
    CRHardie , May 1, 2021
    #3

  4. Ozymandias TDR MEMBER

    Wow, you want to replace a 1500$ pump because of a 5ct O-ring is leaking?
     
    Ozymandias , May 1, 2021
    #4
    Darkbloodmon likes this.

  5. Darkbloodmon TDR MEMBER

    I got 330K on my pump, It was leaking for the past 23K before I realized it was diesel and not oil after some reading on this forum. The previous owners drove it as is and I did to for a while since my crank times were normal. If you're having longer crank times, I'd check the injectors as well even more so if you're on a stock fuel filtration system.
     
    Darkbloodmon , May 2, 2021
    #5

  6. CRHardie

    This is why I asked for suggestions here. I don’t want to replace the fuel pumps I can’t see where the pump is leaking from and was hoping someone who had experienced this before would give me a suggestion where to look or what to try. Thank you for your answer
     
    CRHardie , May 2, 2021
    #6
    bcbender and mfurrh55 like this.

  7. Ozymandias TDR MEMBER

    Most often it is the input shaft that's leaking, It has an (unvisible) wheep hole, the Diesel comes out between pump body and gear case.

    You can buy CP3 seal kit for around 20$ and re seal it if 8t is in good shape otherwise, what yours should be at that milage.
     
    Ozymandias , May 2, 2021
    #7

  8. cerberusiam Staff Member

    If it is actually leaking out the weep hole the pump is trash. Weep hole is final indication it is done. Normally it doesn't leak out the weep hole because it is plugged with paint and\crud, it goes right into the engine and it make soil. The most common leaks on the CP-3 of that vintage are the o-rings on the aluminum to cast iron housing pieces. The o-rings compress and shrink after timer and they are not large enough to take into account age. I would soak the area up well with engine detergent, pressure wash it, and monitor to see if can see where it is coming from to be sure. Could be a loose fitting or something else that is running down there. If it is anything on the CP-3 then a replacement is probably in order.

    I had one replaced under warranty many moons ago. Stopped the bulk of the leaks but it would still create a film on the pump and wires when it was cold. The OE o-rings are just not up to the task of managing the differing expansion rates.
     
    cerberusiam , May 2, 2021
    #8
    CRHardie likes this.
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