Click for Abeking Click for Westport Click for Walker Click for JetForums Click for Glendinning

Fuel Pump problem

Discussion in 'Engines' started by MBevins, Jul 3, 2025 at 10:24 AM.

  1. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    1,234
    Location:
    Windsor On. Canada
    The fuel pump on my DD 6-71 is weeping a bit of oil, is there a chance the fuel could migrate into the crankcase?
    I'm monitoring the oil level but it doesn't appear to be going up.

    I will deal with the weeping when time and opportunity is there, but if fuel is migrating it will become a major priority.
  2. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,855
    Location:
    Satsuma, FL
    There is an engine oil seal, then a separate fuel seal. When either leaks, the same weep hole is used to drain and warn you.
  3. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    1,234
    Location:
    Windsor On. Canada
    Thanks Ralph.
    We're cruising for a bit and I really didn't want to break that down right now. I'll monitor and wipe until we're done.
  4. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,640
    Location:
    Fort Lauderdale
    If it's oil, the oil seal is leaking, NOT the fuel seal. Keep an eye on it, and fix it when you get a chance.
  5. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    1,234
    Location:
    Windsor On. Canada
    Is this a replaceable seal? Or do I buy a new pump?
  6. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,855
    Location:
    Satsuma, FL
    Seals and parts are available for repair. I recall a rebuild kit on some of those old gear pumps. No warranties.

    However, pending how old the pump is; You may consider replacing the whole pump (with warranties) with new.

    On your 6-71, getting to your fuel pump may be an easy job. On the V blocks it's a pain.
    I have always replaced with new for my customers and never had a worry of going back to it.

    There may be a couple of different fuel pumps available for your engine. Serial number and/or build sheet is important here when ordering from a real DDC jobber. Not NAPA or AutoZoned.
  7. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,640
    Location:
    Fort Lauderdale
    I'd replace the pump too, as the bearings going might be the reason the seal went, or the seal is old and will start leaking fuel next, and it's hard to get the microscopic scratches out of the shaft so the new seals last as long. Half the time when I have something rebuilt even by a professional shop it bites me in the rear with an early demise.