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Discussion Starter · #1 · (Edited)
Injector copper wash not sealing or cracked head?

Just was getting ready to put in my injectors and I realized that the copper washers the seal off the combustion chamber are cupped: one side is rounded and the other is cupped.. Does it matter which way the cup faces? I thought I've hear something about that but did a search and can't find anything.. TIA
 

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The service manual says nothing about them being cupped. Are they made by Cummins or aftermarket? It just reads about putting a small amount of 15W40 motor oil on to retain them in place.
 

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Discussion Starter · #3 ·
AM?

I sourced my parts from OFI and I overheard the tech talking to someone else about cupped washers but he didn't say anything to me.. It will be flat when i am done. :rasta:
 

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Washer

flat towards the head, cup up against the injector....not really cupped, just the way they appear after they are punched.....just make sure you use the correct thickness , at the very least same as what you took out. a little oil orlight grease will easily hod the washer in place...In all honesty it would make any difference once the injector is tightened down. Steve
 

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Discussion Starter · #5 ·
flat towards the head, cup up against the injector....not really cupped, just the way they appear after they are punched.....just make sure you use the correct thickness , at the very least same as what you took out. a little oil orlight grease will easily hod the washer in place...In all honesty it would make any difference once the injector is tightened down. Steve
That is how I did it, figured the injector was like a spark plug in the way it seals, and that is kind of how they look. I wasn't sure if the cup was from being stamped out as most copper washers are flat that I have seen. Thanks, now to fire it up and see how it does, then pull the pump and get my leaks plugged on it.
 

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Discussion Starter · #6 ·
Hmmm.

So I put it all back together fired it up and it looked like my copper washers were sealing so I torqued it up to 48 lbs, reassembled, runs fine, noticed the #1 was still bubbling in the dribble of diesel around the retaining nut/collar so I retorqued to 52 (spec is 44lbs). I still have a fair amount of bubbling on the #1, which I recall was wet when I pulled it out originally which I attributed to my leaking valve cover. These early 9mm injectors don't have the groove for the O-ring dust seal so oil could seep in there very easily. I pulled #1 injector out and inspected for contamination, I could KIND OF make out a line in the seat radiating from the center out. Could this possibly be the crack that the 9mm heads are known for? Pull the head? Run it?
I'm gonna take it for a ride after I fix some other things to see if it runs a little cleaner but am taking this one step at a time... Motor starts right up, seems like it would be worth doing things right.
 

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My personal opinion

I would pull the injector blow itout with air good inspect for a crack, if nothing obvious I would take a torch heat the copper up till red hot" they look like they are shiny when they are just right" then drop in cold water. This will turn any copper intoDead soft copper as they call it. The washers can be reused many times. This is refered to as annealing copper the washers can be reused many times in this manner. In some old john deere books "40 ish" This is the stated method for reuseing the injector washers in there 1rst diesels John deere r model. This is were I learned it. I have used this method on My inJector Washers and The Bypass tubes for some time with no problems. It beats Running to the store Right? If You still Have a leak Then I would run it as long as you can and see what happens;)
 

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Discussion Starter · #8 ·
Good tip

I think I might try that, I forgot I have done that with old motorcycle copper gaskets. I talked to a friend who runs a diesel repair shop and recommended trying another washer. He also stated that the crack usually runs toward the valve.. which what I saw does..
I got it pretty darn clean so hopefully I can get that washer to seal.. I regret not closely inspecting the washers as:deadhorse: I took them out.
 
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