Is the fuel line rubbing on something?
Bad motor mount(s) causing excessive movement?

 

Did the dealer install this? They usually give a 1 year warranty.

 

We are both catastrophe adjusters, the fuel line failure always occurred 100s or 1000s of miles away from shop performing the latest repair. The GM engine lower end overhaul was performed while former owner worked in Arizona. Fuel line was later replaced by Classic Cadillac in Atlanta months later. Independent mechanic shops performed multiple replacements. My 1st replacement as owner was performed by local auto repair shop. Shop discovered a weak motor mount after my suggestion to check while i was traveling out of state. Both fuel line & motor mount were replaced. As a former owner operator of a body shop, I performed my 2nd replacement. A total of 8,000? miles since my original owner replacement 2 additional lines have broke. The fuel line is part # 1259-1197 and is a rather simple repair.

 

That's not the most common part # for that fuel pipe. It took looking at google images after the search to finally see what you were referring to. That fuel pipe (as GM refers to it) is probably failing repeatedly because there is some degree of stress on it after install. When I replaced my high pressure pump, I realized the importance of a good finger snug tightness to all of the fuel fittings first, which would keep everything closely attached, but allow the ball and socket joints to pivot, as the pump and inlet fuel line retaining bolts were tightened.

If the pump is tightened down first and there is a little increase in its ideal distance from the injector rail resulting in that pipe being stretched on tightening, that maybe the cause, in which case the pump retaining bolts would need to be loosened (and replaced) for the next pipe, to insure there is no tension on it after install. Of course this is assuming the pipe is breaking as stated and not just leaking at the attached end.

If it is leaking repeatedly at either end, then you need to go ahead and replace the pump and the fuel rail it connects to, because the metal surfaces are probably damaged microscopically in a manner that will likely result in continued repeats, especially if that pipe has been replaced without the proper torque. I had to get pretty creative using a crow foot attachment to torque the end connected to the pump. One thing I rarely see mechanics use is a torque wrench.

GM is pretty sensitive about the fuel pipes which are one time use. The recommendation for a leak at either end of the pipe is replacement of the adjoining part along with the pipe to achieve undamaged mating surfaces.

Since your wife refuses to drive it, I'd say you're at the new fuel rails and pump stage to regain her confidence. If you agree, make sure it's done by the book which will include the need for new injector seals that require a special tool for proper installation.

 

Please confirm the fuel pipe you are referencing, there are three, one that connects the two fuel rails, one that connects the rail to the high pressure pump and one that connects the high pressure pump to the low pressure system, all are metal. The part that I found linked to the number you provided is GM #12591197. There shouldn't be a problem with the pipes on the high pressure side unless some one removed them, or the pump for some type of service. Here is a link to a low pressure pipe repeat failure problem, this is what is prompting me to ask if you are referring to the same part which is different from the one the number you provided leads to.

https://www.cadillacforums.com/foru.../2008-2013-cadillac-cts-general-discussion/423601-2009-cts-fuel-line-crack.html

 

Yes, part #1259-1197

 

I am checking into a possible custom braided flex line. The line break is always at the bottom ball joint since I've owned the CTS.

 

I believe you're going to need to identify the cause of the repeat failures, I don't know for sure there is a braided steel flex line that will be flexible AND compact enough, while at the same time able to withstand the fuel pressures that pipe is exposed to, somewhere in the 2500 psi plus range at max performance loads. That's probably too close to the typical CPF and PTFE line safe pressures in the size range you'll need. The stronger the braided reinforced line, the less flexible it is and by the time you've made sufficient room for the necessary bending radius you may need for the line that is safely proficient, you might have a hose protruding out the top of the hood.

The part number you listed is correct, you just have to get rid of that dash in the middle, in order for the part to show up freely during a search.

 

Obviously, identification of problem is a problem since several trips to Cadillac dealership offered No solution. However too often technicians are not the best at diagnostics. Any suggestions or solutions are greatly appreciated.

 

Not sure the dealer would invest much time in trying to troubleshoot the cause when there is no warranty expense associated to encourage them. I suggest you do the next replacement, or ask if you can supervise to some extent to insure that the pipe is checked for any error in fitment. I believe if you finger snug it to the pump, the collar on the other end can be pulled back to see if the ball and socket surfaces are pretty closely mated, or offset in a manner that can cause stress. I put two yellow arrows on the picture (which I lifted from the internet) to show the two connection points clearly. I personally believe at this point you should consider replacing the pump and the fuel rail.

Since the problem started after major engine work, the trouble is likely rooted in something being poorly aligned, or damaged during reassembly. Replacing the driver side fuel rail along with the pipes and pump will provide an opportunity to attempt a stress free hookup of the components before torquing everything down. 7 failures easily warrants this kind of effort. It's either that, or risk a fire until it becomes a reality. In my observation of vehicle fires with the fire truck near by, they tend to do more watching than wetting, I guess to make sure it's a total loss.

Make sure the high pressure pipe is not coming into contact with the low pressure inlet pipe. Due to the pumping action of the high pressure pump, there should be a pulsing related vibration in those parts that could contribute to failure if those parts come into contact if possible.

 

Broken engine mount? Not sure if this problem can actually cause your symptoms, but worth a look.

https://www.youtube.com/watch?v=xN1E68oekWQ&app=desktop

 

Interestingly the pulsator seen in the picture above was discontinued from the low pressure pipe in 2010. If there's no connection strain on the parts, perhaps there's a vibration related failure that might benefit from having that style installed on the car.

 

My 60,000 psi waterjet has fewer failures than your gas line, Johnny Stone.

 

My last install did not reveal any evidence of connection strain or contact with other line. The line was loosely snugged down on at both connecting points before tightening. Please elaborate about pulsator, not sure what part you are referencing. New replacement line still pending while additional info reviewed with hope of a resolution to this issue.

 

It's the circular canister with the white tag on it. A form of this was used inside the tank connecting the pump to the fuel line in the early years of fuel injection in the 80s to dampen the pulsation in the system, although that is not the part that is failing.

If binding is not the problem perhaps vibration harmonics is and a combination of that and the high line pressures experienced might be leading to the failures. Put a wrench on the fuel rail bolts and make sure they're tight and split a couple of pieces of small diameter rubber hose to fit over the connecting pipe to serve as a dampener. The harmonic balancer at the end of the crankshaft serves a similar purpose, to offset the pulses transmitted to the crankshaft. The fuel line is subjected to high intensity pulses, or pressure spikes.

No pun intended, you need to keep a fire extinguisher in the car and still consider replacing the parts suggested. Contact someone higher up in the engineering arena of GM also who might know exactly what's going on. By that I mean email, or write.

 

Any suggestions on how & where to contact someone higher up in engineering arena of GM. The customer service call was a serious waste of time! speaking with 2 GM dealerships only produced, "Call Customer Service"

 

Go to a national GM or Delphi/Delco website and hit the contact or Dept button and look for an appropriate contact. They usually have a list. For example, when I couldn't find info on the Dual mass flywheel used in one manual shift GM car, I contacted SACHS, the manufacturer via email. They responded by phone if I recall correctly with information I could not find written anywhere about the torque limits of that part, which was stated to be about 10% above that of the engine it was used on, after which it would likely slip. Interestingly a high performance version of that vehicle displayed at SEMA had horsepower and torque ratings higher than the production car, but within 10% of its hp/tq ratings.

It sounds like a long shot but I've done it several times, the people exist and rarely do they not respond, because what customer does that. While addressing a cold start noise problem I had with the CTS, I contacted Standard Motor Parts and talked to a rep about the actuators, who sent me a TSB that was not readily available to the public and explained that several of their GM parts are just rebranded originals which would explain why many of their parts on Rockauto are often within a few dollars of the GM parts. He was not an engineer, but he talked to them for me to round up information.

The dealer may not have a clue, but their are people above them in the "chain" that do. You're doing essentially the same thing they do when they can't solve a problem, call someone else.

Are you torquing this part according to specification, or guesstimating?

 

Forgot all about this in my research and development folder, GM started using this design fuel pipe as early as 2010 in the CTS according to Rockauto (click the part# under 2012 CTS, fuel pipe). Considering they typically don't make changes in existing parts on the same application without a need, it's possible it will solve your problem if it will fit the existing rails which should be the same as your current up to 2012 and may not matter, I can't guarantee that but it would be worth the upgrade consideration. Keep us posted. Note the stress relieving loop in the design.

Part# ACDELCO 12639208

 

I purchased this line, however it would not fit. I went a step further and purchased the left bank fuel rail shown to adapt to the new fuel line. After receiving the fuel rail & additional tear down I discovered the rail was different & would not work. At this point I am again stumped at what the next step should be.

 

So sorry Johnny, I thought my "if it will fit the existing rails" and "I can't guarantee" comments would encourage you to investigate the possibility further before investing in any of the parts. I went back and dug a lot deeper after seeing your update and discovered that what we know as the integrated exhaust ports of the 2012 LFX, actually started in the 2010 LF1 3.0 L V6. I was not aware of that until now and that's why that particular design which is also used on the 3.6L LFX, was listed for the CTS beginning in 2010, during which time I was not aware the LFX exhaust port design was in production signaling a possible cylinder head difference. Prior to this, the the 60 degree V6 motors were pretty consistent in build and interchange of parts across displacement except for the parts responsible for determining displacement.

If you can exchange the parts for new originals do so. It was proposed early on, but perhaps replacing everything from the high pressure pump to the rails is the next best thing. The fuel injectors can be sent out to be refurbished if there is no place locally that can do it, as the seals will need to be replaced before reinstallation and unlike the port injectors, this really does require a special tool. This is probably the best way to insure that all parts are installed stress free. I can not otherwise make sense of why the line would start failing repeatedly all of a sudden after so many miles of normalcy.

If that doesn't fix it, programming (fueling) and an abnormal vibration are all that's left that I can imagine as the cause, given the system is subject to pulse shock, as can be seen in a fuel pressure gauge with the engine running.

 

This serves as a followup to the fuel line failure issue. After attempting other options of repair, I replaced the fuel line pressure sensor. To date, there have been no further fuel line failures. However, the vehicle has not been trusted to take a long trip, just local daily driving without any incidents.

 

When I read that initially, I thought that it could be the solution in the presence of a pressure spike issue associated with a bad sensor. I was not able to rationalize how such an issue would get through the failures and suspect pressure spikes without ever setting a code, so as much as I hoped for you, I'm not surprised now that it has happened again.

Given the problem started after a major repair that almost certainly required removal of the cylinder heads, there's no telling what was dropped and damaged, or what associated fuel part was replaced with potentially the incorrect part that is still on the motor causing this to happen. I've heard of the line being broken during an engine mount replacement where the motor was raised and tilted in a manner that brought it too close to the firewall, but I believe you have ruled out the possibility of contact damage. Pictures of the broken parts might provide some insight as well.

If I were you with this car at this point, I would replace the high pressure fuel pump and possibly the cam follower that it uses, as the pumps are different between the LLT and LFX, but apparently are interchangeable. I would replace the two fuel pipes and both fuel rails if you have not already, have the fuel injectors refurbished and basically make sure everything from the high pressure pump to the rails, including injector retaining clips were fresh.

Before installing, I would check all mounting surfaces and the threads in the bolt holes to make sure they were holding, as someone broke a rail retaining bolt from turning it the wrong way and cross threading bolts is a flat rate mechanic specialty in the rush to finish a job, the absolute worst I've seen was a stripped out timing belt tensioner bolt hole during install on an Acura V6, and a stripped out rocker stud hole on an aluminum head GM V6, all from rushing with power tools.

After it was all put back together, I would drive the car with a scan tool connected and recording data if possible, or you can have someone drive while you observe the pressures for abnormal behavior. I watched a video recently addressing chronic recurrent fuel related codes with difficulty finding the cause until this very approach was used to catch intermittent extremely low pressure from the high pressure pump causing the codes, but behaving normally during routine diagnostic procedures without test driving.

There's no way that fuel pipe should rupture this many times from normal use, which stopped being normal some how after a major repair. I would also leave the sound insulation and cover off in case it is some how involved until it can be established that the issue has been resolved. Fix it and drive it like a test pilot so that if it's still not right, you'll find out in short order.

 

If you had the dealer replace the line they should warranty it for one year.

 

Well, my last reply indicated the replacement of sensor. To my regret, the fuel line has broke again @ 149,200 miles. The smell of fuel was noticed while coming from Chattanooga while fueling up. I was hoping smell was due to my location but drove a few miles, stopped & raised hood where the strong smell of gas & a vapor was detected at rear of engine. The CTS is now resting comfortably in my driveway. Does anyone have suggestions other than allowing the vehicle to catch fire & burn?

 

Not a double post, but a forum hiccup doubling my post.

 

One of my sheet metal workers left his keys in his car at work. Someone stole it. Insurance paid.

 

Bad motor mount ?
To leave the key in the CTS, I'd have to leave my pants.

 

Perish the thought.

 

I have the same issue, did you ever find a solution.
thanks.

 

Realizing this is 5 years old - but in reading I have noticed 1 thing was never mentioned. The high pressure pump operates off of an engine cam lobe. It also operates at around 2500psi. When replacing this pump, the #4 cylinder must be placed at TDC. This puts the cam lobe that operates the pump at its base line - or lowest point. IF this pump is torqued down with the cam lobe in the wrong position, ALL of the problems in this post can occur.

 

Explain how this is so given the pump plunger is spring loaded and once the pump is securely mounted in place there is no visible indication present (that I know of) that could indicate what position the lobe was in at install. If there is no known binding upon install of the fuel pipe, what else is left to cause it to fail, except for some enormous fuel pressure that is not being broadcast by an engine code. I'd also expect there to be far more incidents of this issue as few will have read the install procedure on what appears to be a straightforward repair. I can see the difficulty in trying to compress the pump onto the mount by hand with a lobe up, but that's about it.

 

If the cam lobe is in the wrong position, it can create too much force on the pump spring - thus causing the pump mounting bolts to be torqued under load. Like installing a rocker arm with the cam lobe pressing on the valve spring. This can lead to the pump body mounting torque to be 'less' than 18ft lbs - when the cam releases tension on the spring. Leading to a 'looser' pump body mount. In turn, putting stress on all fuel line connections. Harmonic vibrations will occur.
The fuel lines themselves are torqued at 22 ft lbs, and are 1 shot deals on the high pressure side - meaning when they are torqued, they make a witness mark inside of the pipe connection that is almost impossible to match up again.
IF, the pump body is not installed properly, and it causes stress or vibrations to the line connections - the line will leak - especially the 2500psi high side lines.
And, no - this is really not a straight forward repair. The little details that can get missed, sometimes get lucky and don't cause any issues. In this case I believe these little details caused the issue.