jimbo486

the cummins shop manual reads 44ft-lbs on the injector hold down nut. last i night i noticed my #2 injector has fuel coming out from under the hold down nut. it's not squirting out but seeping. but a significant amount. i looked at the other injectors and they all are a bit moist below the hold down nut. could it be that with the heating and cooling cycles of the motor, after replacing the head gasket and torquing the head back in september, would make them loosen up a bit like head bolts could?? a friend of mine told me that he heard from a guy who works on these motors that the hold down nut torque is up around 65ft-lbs. i don't think that the manual would be wrong, but i just hope that the nuts loosened from expansion and contraction. help!!

BC847

44ft/lbs is correct.

I'd pull the leaking injector and clean the injector's tip right there where it presses against the copper washer. Then clean the heads mating surface for that same washer.
Then I'd clean the washer itself and look for any grooves that might be burned into it.

Flip the washer over and put it all back together with some anti-seize on the hold-down nut threads.

jimbo486

i'll cross my fingers and hope i don't see grooves as i have the adapters/sleeves for my 9mm bores. thanks david!

On Edit: does it seem to make sense that the heating and cooling cycles could've caused the loosening of the nut?

BC847

If that were the case, then Dodge/Cummins would have a retorque as part of the regular maintenance.

I'd suspect some grit or something got in there and the heating/cooling cycles worked it out leaving some slack.

Trebor

Sorta dumb question but did you make sure you had all six of the old sealing washers out of the engine before you installed the injectors and the new sealing washers??

SOOT4BRAINS

Jimbo, another thing to check would be to make sure the nozzle part of the injector is tightened to the body. SMKHZRD's 435's when new had 1 that seeped out from around the nut, it was because the nozzle was loose, not the hold down nut. Just sumthin to check. Place we bought them from said to turn it 1/4 turn or so to tighten it up. I actually turned it less, as it felt like it was tight after 1/8 or so, never leaked after that.

w250_93

I'm with soot4brains, sounds like the body of he injector it's self is loose cause fuel wouldn't come back up out of the combustion chamer because it gets burned when it injected. A good way to test to see if the injector isn't sealing in the head is to start the truck and spray some soapy water around the injector if it bubbles then the hold down isn't tight enough or the copper washer needs replaced. But I think the bodies aren't tight and that's were ur fuel is coming from.

jimbo486

well i popped the #2 injector out and the seal/adapter looked fine to me. the mating surface down inside the head looked clean, no grit or any burrs that i could see. i torqued #1 - #3 to 45ft lbs., cranked it over and let the engine run on the rear 3 and waited until i saw 3 streams of fuel from the fronts. then i shut it off, cleaned up the fuel (which went everywhere!), tightened the high pressure lines, started it again and it was running on all 6. i anticipated this task to be a little more involved than it actually was. as easy as it was, i'll run it for a little bit and keep an eye on things. if that leak develops again, that injector will come out and i'll try to tighten the body up. thanks for all the advice and input!

Ramsalot

I'm not sure if it's the same spec i was looking up or not but you may have misread the torque spec. if it has to do with the fuel delivery tubes those spec at 44 alright but that's measured in Inch pounds, not foot pounds. much less pressure is needed