#4fuel injecter line failure

[Tloguzzo]

I have replaced#4 injecter line 4 times in my 3times thru dodge dealer last time from cummins
Is there a good solution to this problem besides carrying a spare line
I've talked to bully dog etc. no body seems to know
Never experienced a failure on another line just turned 200000 miles
Had 375000 miles on my 1995 12 valve never had this problem

 

[seafish]

Have any of them been the newer, upgraded #4 line that comes with the metal (insted of plastic) clamp??

This one??

http://www.genosgarage.com/product/fil-5289447/Fuel-Injector-Components-Gaskets

 

[sag2]

Are the hold down clamps in place?

 

[Joseph Donnelly]

I grease the threads and the shoulders of the line tips so the lines don't get twisted when tightening the nuts.

 

[snapped_bolt]

The Geno's Garage #4 clamp...

Is that the updated version coming from a later model?
Cummins Quickserve does not list this as part for the 2003 5.9. I ordered a full set of injector lines, and they list the 3957904, but when ordered I was sent the 5289447.
This line is secured by what appears to be a bit of un-reinforced hose.
Has this update ended the vibration/erosion issue?


snapped bolt

 

[snapped_bolt]

I grease the threads and the shoulders of the line tips so the lines don't get twisted when tightening the nuts.

Since these are torqued fittings, grease is correct- if you don't grease them, the line would probably be preloaded.
I am wondering why this location has more vibration than others...or is it the line length and/or twist? Anybody magnaflux one to find out if there are cracks from the factory? There are quite a few twists...

snapped bolt

 

[lpennock]

The basic problem with #4 is the resonant frequency of the line is somewhere around 2000-2200 RPM. This causes the line to come loose with the old style clamps. The new style should clamp the vibration.

 

[lpennock]

I Lost two of the #4 in less than 6 months and both failed at the same spot. Where the tube goes into the head side fitting. On the third one I pulled the bolt in the clamp, replaced with a longer bolt and then added a nylock nut there to provide additional locking. Every highway trip would fine #4 starting to loosen but after the mod I haven't had a failure since. (I still carry a spare line though.

 

[snapped_bolt]

That #4 does look like a spring....

And it would be relatively easy to get it to "sing". Perhaps the "spring" is enough to cause excessive vibration. The other lines do not have as much "spring" in their design. I am almost positive that the entire intake cover resonates uniformly, but #4 accentuates this more than the others.
Perhaps some fishing weights on the bend nearest the fuel rail would help? Something needs to cancel the vibration. Even casting a lead gusset on the bend may do it.

snapped bolt

 

[WalterJ]

Hmmm, what about encasing the exposed line in Silicone rubber? I also had my #4 & #6 fail 18months apart, 2 years ago. Mayhaps my new to be installed ATI damper will kill that 2K vib.

 

[TCDiesel]

I have replaced#4 injecter line 4 times in my 3times thru dodge dealer last time from cummins
Is there a good solution to this problem besides carrying a spare line
I've talked to bully dog etc. no body seems to know
Never experienced a failure on another line just turned 200000 miles
Had 375000 miles on my 1995 12 valve never had this problem

Call Me for the permanent Fix....Ask for Todd.

 

[Bob4x4]

The #6 line has also been upgraded on the early crd models it now has an added support

 

[seafish]

The #6 line has also been upgraded on the early crd models it now has an added support

Got a part # ??

 

[Bob4x4]

Got a part # ??

I don't but it is a production part for iirc 06 or o7.You also need to buy a stud and nut for the bracket.The stud replaces the outer bolt on the engine lift plate,the size steps down in size for the hold down bracket

 

[Dave04]

I have had 3 #4 lines go out. Last one 2 years ago.