although it's my 2nd truck, I'm still pretty green... leaking fuel injectors?!

[Forrest Nearing]

was looking under the hood today w/ the engine running, and I noticed the #1 and #2 injectors leaking fuel. I promptly started to panic and headed home to my tools.



now, the guy I bought the truck from had just replaced the timing case (KDP got him), and I knew he had to have bled the injectors when the pump went back on, but I had no idea where exactly it was leaking from or how to make it stop!



I got home, killed the truck, hosed the area w/ brake cleaner, started the truck back up, and looked to see where it was leaking from. Appeared to be leaking from where the hard line meets the injector. a little snugging with a 3/4" wrench, and no more leak! WHEW!



I'm like a worried mother with a new baby with this truck!



can't wait till I've got some good miles on it and it really feels like a part of me as all my other vehicles do.



Forrest

 

[gitchesum]

Yep. been there done that.

Should have been there the day I forgot to tighten the injector lines on the injection pump. Soaked the dirvers side of the engine. I was so busy watching the passenger side while I was cranking, I didn't even see the fuel shooting up on the other side.



That was probably my 4th injector change, not a first timer's mistake. :{

 

[Forrest Nearing]

well, I look a look at it again later today, and I saw the tiniest little bubbles coming from between the #2 injector body and what appears to be a 15/16" locking collar of some sort...



do I need to tighten that collar?



it also appears to be doing it at the #1 injector though not as bad



still worried,



Forrest

 

[Sticks]

I think it is a 19mm wrench. They need to be tightened to 19 inch pounds with a torque wrench (again I think - hopefully someone will chime in if I am wrong about the torque settings).



You might want to back the nuts off completely, re-seat the injector tube going into the head to make sure it is seated correctly, then re-install the nut and injector feed line. There is an outside chance you have a cracked line, take a closer look, but don't do it by feel with the engine running. EXTREME risk of injection into your skin.

 

[Forrest Nearing]

well, now I don't see any fuel or bubbles around the injectors. could be worse I suppose!



the fitting on top of the injector is 19mm, but there appears to be a 15/16" collar around the injector at the cylinder head... not sure if tightening that would better seal the injector to the head.



for now it appears alright... I'll keep an eye on everything.



Forrest

 

[Sticks]

Originally posted by Forrest Nearing

well, now I don't see any fuel or bubbles around the injectors. could be worse I suppose!



the fitting on top of the injector is 19mm, but there appears to be a 15/16" collar around the injector at the cylinder head... not sure if tightening that would better seal the injector to the head.



for now it appears alright... I'll keep an eye on everything.



Forrest

For clarification, the injector is actually in the center of the valve cover, perpendicular (pointing straight down) to the valve cover. The injector lines from the pump to the 19mm nut is one line, then there is a 4 inch or so line under the valve cover/inside the head that goes to the injector from the 19mm nut. Occasionally when you change the injectors, you need to replace those smaller lines.



Just keep and eye on it, and you should be fine. Start worrying if your oil level starts to rise. Be consistent about when you check it IE in the same parking place, and after the engine has not been running for several hours. It takes a while for all 11 qts of oil to drain back down.

 

[Forrest Nearing]

injector in the valve cover? mine appear to be beside the valve covers... I've got a 12v engine, perhaps the 24v's are different? (like I said, I'm pretty green to all this!)



Forrest

 

[Sticks]

Ummm... 12 valve I dont know. My bad, I presumed it to be a 24v. It may be. If you still have trouble, post over in the First Gen section.

 

[gitchesum]

Originally posted by Forrest Nearing

well, now I don't see any fuel or bubbles around the injectors. could be worse I suppose!



the fitting on top of the injector is 19mm, but there appears to be a 15/16" collar around the injector at the cylinder head... not sure if tightening that would better seal the injector to the head.



for now it appears alright... I'll keep an eye on everything.



Forrest

That is the injector holddown nut. You can tighten if a little if you want but you'll have to remove the injector lines to do it. If it's not a problem, you might as well leave it alone.

 

[Joe G.]

I don't think the injector hold down nut can possibly leak fuel. It is not designed for that. The injectors on a 12 valve are right there where you can see them. There are two lines for fuel: the high pressure line from the injection pump and the low pressure return line to the fuel filter. If your fuel is not leaking from where the high pressure line attaches to the injector the only other place it can be leaking is the small banjo fitting for the return line. If there are leaks from somewhere else you have something wrong with your injectors.

 

[Forrest Nearing]

sticks, my truck is a '97, so it's a 2nd gen. I guess I should have posted on that forum, but I figured it was a pretty elementry question, so I tried to post it in the appropriate forum. again, still pretty new to this whole thing!



Joe, it wasn't leaking fuel from around the body of the injector, but there were little bubbles coming up through the fuel that had leaked from the top fitting... upon furthur meditation, I think the bubbles were basicly from the diesel that seeped past the square cut o-ring "boiling off". The truck seems to run great, so I'll just continue to keep an eye on it.



Forrest

 

[Joe G.]

Forrest,



You have a 2nd gen 12 valve. Jan 1, 98 the 2nd gen trucks started using a 24 valve engine. 1st gen is the body style used from '89 thru '93. 2nd gen is the body style from '94 thru '02. 3rd gen is the later trucks.

 

[Forrest Nearing]

Joe,



I'm familiar... I had a 1st gen a couple years back. I'm pretty well versed in these trucks as I've been obsessed with them for almost 4 years. I'm just lacking in hands-on experience with Cummins-specific maintanence. Been working on cars for a solid decade+... built many a car from the ground up, just pretty green when it comes to the Cummins itself. But that'll change over time!



Forrest