Ok today i was in a hurry and while my truck was warming up in the driveway I notice a puddle under the truck. It was Diesel and it looked like it was coming from the bottom of the lift pump. About evey 5 second there was a drip while it was running only. I took another vehicle and didn't get back intime to look into it futher. Question will these leak at the bottom? It looked dry above it. Anyone had this happen to them? Thanks in advance for any input.:confused:

Edited December 29, 200915 yr by Bugman123
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Sounds like a stock lift pump correct? Visually check and feel to see if you can tell where it is coming from. The fittings could be lose or there could be a pin hole leak in one. Good luck.

Lift pumps normally don't leak out the bottom. Unless the contector seals are shot... (Possible)

In addition to what Mike mentioned, check your fuel filter cannister for leaks along the plastic threaded top and don't forget the ensure the fuel cannister drain lever is in the full off position (pushed in). Could be a faulty o-ring packing on the fuel cannister plastic threaded top or the fuel drain lever is partially open. I can personally attest to the fact that they will lead if you leave the fuel drain lever open even just a little. :biggrin:

  LiveOak said:

In addition to what Mike mentioned, check your fuel filter cannister for leaks along the plastic threaded top and don't forget the ensure the fuel cannister drain lever is in the full off position (pushed in). Could be a faulty o-ring packing on the fuel cannister plastic threaded top or the fuel drain lever is partially open. I can personally attest to the fact that they will lead if you leave the fuel drain lever open even just a little. :biggrin:

Yea I drain mine one time and liked to never got it to stop driping, ( trash in needle and seat)

Thanks for all the info. Yesterday i started to look it over and found that the banjo fitting on the back of the pump was seeping:bang:. I guess when i had to get to the map sensor to put the Quadzilla Milage Max on, i moved the line a little:rolleyes:. I then tighten everything up and then looked for it to leak, but it wasn't:biggrin:. Used a paper towel to find where it was wet:2cents:. After that I degeased the area off took for a drive and then recheck. Checked out leak free.

Those are the best type of fixes. EASY and low cost!

  gassernomore said:

Those are the best type of fixes. EASY and low cost!

No joke...:thumbsup:

When I replaced my first lift pump I was amazed to see that the banjo bolts on the stock pump fittings were barely tight. I was surprised that they weren't leaking.

Don't get over zealous with banjo bolt there is times where I've seen people break them in half...:eek: They are weak at the point of where the 4 holes are in the shank of the bolt.

The banjo bolt that I bought at the parts store today part# 256425 for $5 had bigger holes than the stock Cummins one actually. It doesn't need to be super tight, especially with only 12psi of pressure, the area of that bolt would probably be less than 1/2 a sq. in so maybe 5 pounds which is very little, especially if you figure that a 1/2" grade 8 bolt has a tensile strength of about 55,000 pounds. The only part I was concerned with is having to drill so deep into the head of the bolt to tap it for the 1/8 pipe thread for the fuel gauge but I have the original bolt in the glove box with the wrench and washers to replace it if I need to. I also installed a 1/4 turn petcock before the gauge fitting in the banjo bolt so I can just shut that off if the line has a leak.