Injector problem

LB7_01DURAMAX

Member
Apr 11, 2019
37
8
8
Ohio
I put some reman 30% over injectors in my truck from Lincoln diesel in 2015, since then I have only put 30k on the truck. Religiously changed fuel filters and ran hot shots secret additive. I got truck out a couple weeks ago and changed oil and has fuel in oil. So I pulled valve covers and ran the truck with some dye in the fuel filter and number 6 injector is leaking up past the solenoid in between the nut and solenoid. Anyone had that problem? Cracked body? I would assume it is the updated body since I bought them in 2015. Never noticed fuel in oil last year. Also I only drove truck maybe 60 miles before I changed the oil this year.
 

2004LB7

Well-known member
Dec 15, 2010
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have you tried torquing the solenoid nut down? I've removed and reinstalled the solenoid many times and never had it leak. didn't take much torque
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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have you tried torquing the solenoid nut down? I've removed and reinstalled the solenoid many times and never had it leak. didn't take much torque

What seals it? Diagrams make it appear to have orings, which I don't see how being slightly under torqued would cause a leak
 

2004LB7

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Dec 15, 2010
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take a look at this thread of mine on another site from a few years ago. https://www.dieselbombers.com/lb7-performance/111843-duramax-lb7-injector-disassembly.html you can see in the nut an o ring that seals against the solenoid but nothing for the solenoid to the injector body. If I remember right it was just locetite on the threads. this is the low pressure or return side of the injector so it shouldn't take much to keep it leak free. maybe there is restriction in the return causing excessive pressure and leaking?
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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Central OH
Looks like there's an oring on the body where the bottom of the nut would engage too. I have a hard time believing these orings would leak before anything else in the system if there was a restriction downstream
 

2004LB7

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Looks like there's an oring on the body where the bottom of the nut would engage too. I have a hard time believing these orings would leak before anything else in the system if there was a restriction downstream
good catch. yeah there is another o ring on the body just below the threads that the nut seals too. probably easiest to just replace those o rings and see if it stops
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,281
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Central OH
good catch. yeah there is another o ring on the body just below the threads that the nut seals too. probably easiest to just replace those o rings and see if it stops

When you removed the retainer nut for the solenoid, was there much spring pressure? He was debating on trying to fix it without removing from the engine, or at least check to see if one of the orings were torn.
 

2004LB7

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Dec 15, 2010
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no pressure by the time you run out of threads. really easy. I replaced two solenoids in mine with the injectors still in the truck. the thread below I explain how to remove and install the solenoid in the truck

 

LB7_01DURAMAX

Member
Apr 11, 2019
37
8
8
Ohio
no pressure by the time you run out of threads. really easy. I replaced two solenoids in mine with the injectors still in the truck. the thread below I explain how to remove and install the solenoid in the truck

Did you not have the right size socket to remove it? Is that why you made that tool? Or is it not a 12 point nut?