fuel leak from pump outlet

Fuel and Air Systems

  1. rich006

    rich006 Learning as I go

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    I disconnected my fuel line at the pump outlet to conduct a fuel pressure test. It tested good (about 4 psi) but now that the line is reconnected there is a leak. I believe the problem is on the pump side of the fitting, not the flared tube end, because I have swapped the flared tube connector with the one that was at the carburetor inlet, and the leak stayed at the pump end. What can I do? I sure don't want to replace the pump again, as that was a real PITA last time.
     
  2. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    Don't know. Is this a performance pump that comes apart? Does it have pipe thread outlet with an adapter to inverted flare, or is the tube fitting part of the pump?

    And did you use a backup wrench on the fitting? Easy to crack/ break the fitting / casting etc etc.
     
  3. MoparMike1974

    MoparMike1974 FABO Gold Member FABO Gold Member

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    I have seen them crack where the line screws in.
     
  4. RustyRatRod

    RustyRatRod Bla de blizhibliz de blatde blizi bla bla

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    Yup. You've managed to crack the pump where the line screws in. Not hard to do as it's only aluminum.
     
  5. oldkimmer

    oldkimmer FABO Gold Member FABO Gold Member

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    Is this on a barbecue or? Kim
     
  6. RedFish

    RedFish Well-Known Member

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    If the fitting has a hex shape, that says you need to support it with a wrench, 2 wrenches required to tighten or loosen.
     
  7. rich006

    rich006 Learning as I go

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    Yep, I was using two wrenches. But I guess I must have overtightened it. I'll replace the pump.
    IMG_3494.JPG
     
  8. toolmanmike

    toolmanmike FABO MODERATOR Staff Member FABO Gold Member

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    Recheck your pressure after replacing the pump. Check it at the carb. Much easier. I have found stock mechanical pumps put out 10-12# and that is way too much pressure for all carbs.
     
    • Agree Agree x 1
    • RedFish

      RedFish Well-Known Member

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      On my 67, removed the alternator. Fuel pump is easy enough. On my 73 with a/c, that alternator bracket was in the way as much as the alternator. Took it off also. I dont recall if I lost coolant at those bolts. Too long ago. My mind worked a lot better back then. I might have drained some coolant in forethought and real sealed those bolt threads. Anyway... Good luck with it
       
    • rich006

      rich006 Learning as I go

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      Actually this is a good example of a shortcut making the job harder. I've done the "slant six fuel line mod" where you run a hose from the pump to the filter, then another hose over the valve cover instead of the hard line going around the front of the engine (the mod is supposed to reduce fuel boiling in the carburetor when you park with the engine hot). With that mod, I have NPT/hose adapters at the pump and the carb. I originally was going to check pressure at the carb, but I didn't have a female NPT connector that I could use to connect my Harbor Freight vacuum/pressure gauge. I decided it was easier to undo the NPT fitting at the pump than to remove the hose from the carb fitting (those hoses are a pain to get off). And you know the rest of the story.
       
    • rich006

      rich006 Learning as I go

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      New pump solved the problem. It wasn't even that hard to replace. I never did see any cracks or other damage in the leaky pump.
       
    • MoparMike1974

      MoparMike1974 FABO Gold Member FABO Gold Member

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      Actually the part the line screws into is steel. What usually happens is someone trys to turn the fixed hex and it cracks the spot weld. Or, they try to loosen the line nut without holding the fixed hex with a wrench.
       
    • RustyRatRod

      RustyRatRod Bla de blizhibliz de blatde blizi bla bla

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      Actually, it depends on which pump he has.
       
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