Leak at rail...

[steved]

Well, today was interesting to say the least. Made a couple trips to Lowe's for landscaping stuff (showed up a Ridgeline by accident)... thought I caught a whiff of raw fuel on something hot a couple times.



The last run, I knew something was not right... popped the hood and I have a fountain from #5 injector line at the rail connection... and I'm not kidding about the fountain. At first I thought cracked line, but decided to try tightening the nut up... it seemed tight, but I backed it off and retightened it and it stopped leaking...



Truck still has an injector clacking, but it runs a whole lot better and smoother now. This came on real sudden, no indications anything was wrong. I'm probably going to call Cummins tomorrow and order ALL those lines since they have been removed multiple times and are pretty corroded... not sure if it isn't a cracked line I'm dealing with.



Any thoughts? This isn't the first I have heard of them coming loose or cracking, but its not that common either...

 

[Bob4x4]

I have had replace a few lines at #4,but in each case the support bracket was loose. All different trucks.



Bob

 

[JCasper]

I've heard of the support brackets not being tightened properly after an injector swap and then the lines leaking.



This is just what I've heard, mine have never been removed. I am still running stock sticks until I have time and funds to send the sticks off to DDP for some upgrades.

 

[steved]

Well, so far so good... I could have imagined the line leaking because it was loose, but the connector nut seemed tight. I'm almost going to say its cracked, and all I did was slide the crack over the fitting where it would stop leaking... the nut was tight. All the supports were tight, but this is at least the 2nd time these lines have been off... no telling how much of that they can take.



I'm going to order an entire set of lines...

 

[speedyjdl]

The lines aren't to awfully expensive. I just ordered a set for the engine that I'm building and all the parts came in the next day except line #5. Its been on back order for a while now.

 

[MickeyMiller]

Steved... just curious, why have the injector lines been off 'at least' 2 times?

 

[steved]

The lines are $146 for the set...



I had the injectors replaced, and then checked... I also seem to remember DCX having things apart early on...

 

[lmills]

At the very least, the lines have been off twice and installed 3 times total, if you include the factory install. Steve, I can honestly tell you I have never missed a connection when installing the injector lines. I always do them in a sequence and have a certain way that I go about them. Also, high pressure leaks at 23K psi would have showed up before now if it was just a loose one. I do remember the lines themselves had quite a bit of corrosion on them from the PA winters, but the connection points where they connected to the rail and to the connector tube looked very good.

 

[steved]

I don't think they were loose... the nut was still tight when I attempted to tighten it.



The more I think about it, the more I think it is cracked and by loosening the fitting, I reseated the line and sealed above/below the crack. In other words, I got lucky.

 

[steved]

Other than replacing the line, anything special about priming or installing?

 

[lmills]

Nope! Nothing to worry about for priming, the common rail system is fired by the electronics once the rail pressure sensor see pressure in the rail.

Also, Steve, I have not forgotten about your parents injectors. I have been under the weather since Fall Brawl and haven't been able to do much.

 

[steved]

... except line #5. Its been on back order for a while now.

They had to order #5 in, but it was in today. I will pick them up tomorrow...

 

[steved]

Nope! Nothing to worry about for priming, the common rail system is fired by the electronics once the rail pressure sensor see pressure in the rail.



Also, Steve, I have not forgotten about your parents injectors. I have been under the weather since Fall Brawl and haven't been able to do much.

Thanks Lloyd...



I should have the lines tomorrow, probably install them over the next couple weeks since the truck is doing short trips now (if it fails, I now have a replacement)...



Ordered both a MAP and IAT sensor for the parent's truck... truck seems to have a dead spot off idle ( a LOT of turbo lag), but once it has boost built it is a fun ride... going to replace those and check for a boost leak somewhere...

 

[steved]

I haven't picked the lines up yet, but wanted to ask a question about tightening them up... I assume you just snug them down with a flare wrench???

 

[lmills]

Steve, the torque spec on those is 22 ft lbs or 30 nm, and you can use a crowsfoot wrench. However, most guys do not even realize there is a tq spec and most tighten it by hand,

 

[steved]

Ok, check this out...



Moved the truck today, first time since I got it home from Lowe's. Much to my surprise, no injector clacking? And no rough idle... it hasn't started like this since the injectors were originally replaced...



Now, this got me thinking... could this have been allowing air into the system at startup? I don't see how since the system has 20k psi on it and should have leaked.



But that's exactly what it acted like, air in the system?



The truck was erily smooth...

 

[steved]

Got the lines today... $150. They look easy enough to put on... had couple questions.



Do you loosen the clamp/bracket to install?? They came with new brackets already tightened...



Those that happen to have done this, how many actually used a flare wrench to tighten them???



Which line is #4??? I'm not sure that mine wasn't #4... I'm thinking it was the second one from the rear on the top...

 

[lmills]

Got the lines today... $150. They look easy enough to put on... had couple questions.



Do you loosen the clamp/bracket to install?? They came with new brackets already tightened...





Personally, I leave the isolator on the line and unbolt it from the plenum cover





Those that happen to have done this, how many actually used a flare wrench to tighten them???





Like I said, most do not even realize there is a torque spec for them because the spec is hidden in the front part of the chapter in the service manual and not covered in the installation segment. Personally, I have installed mine numerous times with a standard wrench. After installing 3-4 dozen sets you kinda get the feel.



Which line is #4??? I'm not sure that mine wasn't #4... I'm thinking it was the second one from the rear on the top...



Number 6 feeds off of the back end of the rail. Number 5 is the last one on the top of the rail, followed by 4 thru number 2. Then number 1 feeds from the other end of the rail. Sounds like you had #4 leaking.

I put my replies in bold above. As for the tightening, I would run the nuts down snug then tighten them slightly. It is always easier to fix a slight leak then to damage the sealing surface on the end of the injector line from tightening it too much unless you feel comfortable using the tq wrench with the crows foot. Either way there will be one or two that you will not be able to get the tq wrench on.

 

[Bob4x4]

Which line is #4??? I'm not sure that mine wasn't #4... I'm thinking it was the second one from the rear on the top...

:-laf Cylinder # 4 second from the rear or 4th from the front



Bob

 

[steved]

Thanks Lloyd.



I'm not uncomfortable using a regular wrench after seeing how heavy the nuts are... I was more worried about pinchiing the nut. My point about the bracket is whether the installed bracket is positioned correctly, and whether I should install it loose, tighten the line, then tighten the bracket on the line?



It all happened under stress that day, that I can't remember if it was #4 or #5... I will scrutenize those two lines when they are removed.