Changed lift pump & filter, extra O-ring????

[dan brooks]

I just finished changing the lift pump and fuel filter, but as I was priming the pump (the TRUCK'S pump) I looked down and saw an O-ring sitting on the inner fender. It's 5/8" OD, 3/8" ID, and I have no idea where it came from. I looked through the FSM and don't see any possibilities, either. I don't want to start the truck until I know for sure that it didn't just end up there during another project... .



Any ideas?

 

[Idually]

I just changed my filter also. I think the o-ring that you are speaking of goes over the center opening of the filter and separates the "fuel in" and "fuel out" portions of the filter. There is probably one still on the "male" portion that is attached to the block(Where the filter thread on to).



Hope this helps. I'm still a newbie, but learning.



Andrew

 

[dan brooks]

Are you talking about the "square cut" rubber washer? If so, that one is in place, and is much bigger than the one I found. This one is much smaller and is a normal round O-ring.

 

[dan brooks]

The O-ring on the right is the one in question. The one on the left is the one for the WIF sender, the middle one is the "square cut" washer that goes on the post.

 

[Idually]

Nope...

I was talking about the middle one(obviously you know about the one). I didn't get one of the little one with my filter and I can't think of where it might go on the fuel filter.



I haven't changed my lift pump, but could it be something there?



Andrew

 

[dan brooks]

I've looked everywhere and don't see any place it can go. The lift pump uses a flared fitting on the output and a pipe fitting on the input, so no O-rings in either place. The plastic fuel line attaches to the input fitting using a clip, but I looked at that and the O-ring was too big to fit there.



I started the truck and it's running fine, but I'm getting a little leak from somewhere - just a drip or two after driving around the block.

 

[dpuckett]

Idually-

Filter actually attaches to the HEAD, but that is irrelevant for now. Just thought I'd share that tidbit. Dont worry about being a newbie- the learning never stops... ... .



dan brooks-

I cant think of ANYTHING that O-ring would go to, at least that's fuel system related. It is about the right size (thought not quite) for a 6. 9/ 7. 3 IDI F-F-FFF-FORD, but that wouldnt apply here. The o-ring isnt part of any lift pump I've ever done, and I've done more than I want to remember; always ME forking over the $60 for it. :{ The square cut o-ring where the fuel heater screws into the head is as big around as the filter, so it wont go there, either.



Anyone else???



Daniel

 

[dan brooks]

I'm guessing it came from somewhere else, I just happened to notice it after swapping pumps. I was worried about sucking a ton of air into the system and having to bleed all the injectors... .



The only other thing I've done lately was tinker with the pump settings a little, but I don't know where it could have come from there, either - not to mention I doubt it would have sat on the inner fender for the past two weeks.



Looks like my leak is coming from the banjo bolt on the fuel line from the lift pump. Guess I damaged one of the washers while I was reinstalling the line - had to remove it to get the line back in place. Yet another job that turned out to be a bigger PITA than I anticipated.

 

[dpuckett]

At least Murphy was busy with you, and not taking more notes on me. You do know that those washers on the banjo bolts are only designed to be used once? I always RE-use them at least twice, though.

 

[dan brooks]

Originally posted by dpuckett

You do know that those washers on the banjo bolts are only designed to be used once?

I do now. Just need to figure out where to get new ones - the mental defects at Auto Zone/Checker/Pep Boys can't spell Cummins, much less find the right stuff.



Murphy always seems to show up around here, regardless of the project. I think he installed a motion sensor in my workshop... .

 

[JLEONARD]

Just need to figure out where to get new ones

If you can find a pump shop or diesel engine repair shop they will stock a bunch of them.



I've re-used those washers many times successfully in the past on all different kinds engines. Sometimes a couple of strokes over some fine sandpaper will clean them up. I've also annealed (soften) them with a propane torch so they will "flatten" slightly like the new ones should.

Jay

 

[dan brooks]

Thanks - I'll be taking the truck in to have the valves adjusted before vacation, so I may just let them screw with it. Over the past few weekends, this thing has almost used up my yearly allotment of patience.....