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Thread: Help-MFI Fuel Leakage at Fuel Pump

  1. 04-04-2021, 06:52 AM #1
    tom1394racing
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    Help-MFI Fuel Leakage at Fuel Pump

    I am in the process of shaking down my newly restored ‘70E and noticed some fuel weeping from the junctions of the fuel hoses and the fuel pump. When I run the pump I see very slight weeping of fuel past the original Norma clamps. Tightening the clamps seems to reduce but not eliminate the small leaking. I have no problems with fuel leakage anywhere else where I have used the original Norma clamps. I plan to disassemble the junctions and replace the clamps with new fuel injection clamps and also replace the hoses. Has anyone else experienced this problem and can offer some suggestions?
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    Tom Butler
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  2. 04-04-2021, 09:15 AM #2
    steve shea
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    Yes but it wasn't the clamps and lines. I tried a different pump and no leakage with the same lines and clamps. My pump finally let go. I'm glad I had a spare.
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  3. 04-04-2021, 12:01 PM #3
    tom1394racing
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    This one is a brand new pump rebuilt and tested. Leakage is clearly coming through the junction between the fuel lines and the pump
    Tom Butler
    1973 RSR Clone
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  4. 04-04-2021, 12:15 PM #4
    xpensivewino
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    That’s an odd one Tom. Since there are very few variables it should be reasonably easy to eliminate the culprit. It does seem like the fuel pump is weeping at least from the photos. I have seen lines with over tightened hose clamps start to leak as well. I’d say try some new line there with a different set of hose clamps and see what happens.
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  5. 04-04-2021, 12:46 PM #5
    davep
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    In your first photo, the top clamp seems to be too far down on the barb of the pump; I would move it closer to the pump. I don't know the device you have attached to the short hose. The second photo makes it look like the leak could be coming from the connection to the device on the short hose.
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  6. 04-04-2021, 03:54 PM #6
    edmayo
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    I think your hoses are too big. The suction hose should be 9mm I.D. the others should be 7mm I.D. I only use Wurth braided hose.
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  7. 04-05-2021, 02:25 AM #7
    tom1394racing
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    Thanks Ed...That makes sense to me as the fuel hoses in the rear of the car all all braided and I have no leaks there.
    Tom Butler
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  8. 05-07-2021, 02:20 AM #8
    tom1394racing
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    Just to close this one out. Swapped out the lines for the correct braided 7 and 9 mm ID hose. Leaks gone all is good.
    Tom Butler
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