2006 continued #4 injector line failure

This has been a super truck which now has 571,061 miles on it and still going strong. All major components are original. Had to paint it once around 500,000 miles. I did have all injectors changed due to some poor advise around 350,000 miles.

It has had one chronic problem which is the #4 injector tubing line which leaves you on the side of the road. The first failure happened around 140,000 miles, second failure abound 380,000, third failure at 568,230 and quickly broke the forth time around 4,000 miles later 572,442 miles.

I have carried a spare injector tube but need to find the source of the problem. I have been getting the replacement tubes from Cummings and this last one is now ordered from Geno's Garage. I have not made a repair yet.

Anyone seen this?

 

Perhaps something in the fuel line mounting brackets is bent. I would ensure the injector line has no forces on it in any direction when the fittings on both ends are threaded on, but are left loose. Maybe you have already checked this. If not, this is a good place to start.

- John

 

Make sure the line retainers are there with no missing parts, and are snug when installed.

 

Make sure you get the latest revision of the #4 line. Cummins changed it several times.

 

Thanks for the information and potential fixes. The last line installed was the third failure. The part I installed then was a Cummins part which I bought after the second failure and had been carried in the truck for over 8 years so I may not have had the most update part. I have one coming from Geno's Garage now.

When I install the new line I will make sure it is not in a bind, but held down and supported properly.

Somewhere I read that the injector lines have over 22,000 lbs of pressure. Is this correct?

 

It is even more, ours can go to 25k, the new ones are 30k now.
You shouldn't have a problem again with the new line.
They pretty much Sorten it out now to make it last, there are very little complaints anymore for broken lines compared to just 10 years ago when it was all over the forums.

 

I always lightly grease the threads and the back end of the flare where the nut rubs it when tightening.