QSB 6.7 Fuel Pump question

[nharrison555]

An acquaintance of mine made a mistake. He was changing his fuel filters and started his engine without turning the fuel feed and return lines on. He stated he let it run for about 5 seconds, noticed it sounded rough, and then again for about 10 seconds. He said he ended up with about a pint of diesel in his bilge with spray around the fuel pump. He cleaned it up, and the engine ran fine. However, he noticed a slight diesel residue at the bottom aft edge of the fuel filter after running it. The residue was cleaned up, then he noticed it again the next time he ran it at 1000 rpm’s for about 5 minutes. 

 

So, his questions to me are, should he replace the entire fuel pump, or just the three o rings? I looked up the pump (part 4929866), and it made me wonder if there is a shaft seal in the pump that would also need replaced. Is there a replaceable shaft seal there?  

 

These questions are over my head a little but thought I would ask this forum.  He has a mechanic who will do the repair, but wants to make sure he has everything there for the mechanic. Any help would be appreciated. 

 

Topic

[nharrison555]

Thanks Clark, my parts book shows a breakdown of the fuel pump with three o rings, but curiously doesn’t show the shaft seal. His engine is the same as mine. We will see what happens. 

[nharrison555]

Thanks Tony.

That is good advice for him. I don’t think he will ever turn the return off again.

I don’t have other pictures. He has talked with Cummins and they will take a look at it. The most likely outcome is a replacement fuel pump, an assessment of the return hoses, and of course, an oil change. Once his repair is complete, I will return with what it entailed. <br /><br />

[Tony Athens]

1——–I want pictures– no crystal ball here  

 

2——HEED this warning————This for any common rail engine…JD’s CR systems are the worst…..  Never turn off the return line and always be sure that your installed fuel system does not have that provision– if you have to switch tanks, have a system that opens the other tank BEFORE it closes to one you are switching away  from   —  If you do not, in most cases you will violate the input shaft seal to the CR pump and guess what happen then?  Fuel will dilute the crankcase oil    

[Clark Leighs]

I would guess and I am guessing that the shaft will have a seal also, an actual shaft seal, especially if the drive mechanism is belt or gear drive and from the exterior.   Parts book ??  

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