Fuel related questions ,can you "limp home if"

[diesel4me]

Just wondering ---lets say your 6.2 has some really rusty injector lines,and while your on a drive,one of them decided to start pissing diesel out....what will happen,besides the risk of flash fire and burning the truck to the ground!...............................................................................................Some guys I've asked who supposedly "know" diesels say it'll just start blowing white smoke,idle very rough,and most likely let air get in the injector pump,causing it to lose its prime,then stall and refuse to re-start until the line is repaired,and the system bled out again..........................................................................................Another guy says it'll keep running as long as you dont shut it down,and the risk of fire is very possible,as the diesel is under 1000+ lbs. of pressure and will be finely atomized and very easily ignited,should it hit a hot exhaust manifold or pipe....................................................................................................I'm asking this because my truck fits this description,and I'm unable to install some good used injector lines now due to health issues,and I've been forced to use the truck as my daily driver (for short distances under 10 miles!) because all the other vehicles I own or can use are in a poor state of repair and have expired inspection stickers................................................................................................Should the worst happen and a line fails,how could you ghetto-fab a repair to it in order to limp home??...I know no rubber hose and clamps would work!...but could you flare the line after cutting the bad peice out and splice a section of brake tubing in ,or use copper tubing,as an emergency fix??.........I dont see J-B Weld being able to withstand that kind of psi for long if at all......so,are we basically screwed when a line fails??.............and have to be towed home??...............................................................................................If and when my back ever feels good enough,I plan to pull the intake and injector lines off and replace them,and at the same time,put on a J code intake I scored off a 1 ton ramp truck that had a 6.2 ...but it also needs the oil pan replaced (I have 2 good ones but cant lie under the truck long enough to install one),and both exhaust manifolds are flaking apart and look like they were in the ocean since 1900...might be easier to yank the engine right out and fix all at one on a stand,rather than bending over it for a week.........

 

[kennyw]

Atomization of the diesel doesn't happen until it reaches the injector. You will have a major fire hazard and I would not drive it even if it was still running.

 

[82355]

I've bronzed a bunch of injection lines on older John Deeres. Worked fine, if not a little hokey.

Martin

 

[diesel4me]

You mean you brazed up the holes in the tubing??.......................................................................................................I talked to one guy who said he has done a lot of booty-fab repairs to bog equipment in order to avoid a shutdown in production ,and one Deutz diesel engine on a bog pump had a injector line rust thru and start spraying fuel,so as a temporary fix,after having J-B Weld fail to work, he cut the line in half with a hacksaw,then slid a length of the next larger sized brake line tubing over the original line,bridging the two peices and the rusted area that was cut out,and brazed the tubing together with a torch!.......................................................................................................................................................................................................He said it was not easy, because the fuel kept igniting and would blow the brass away from the joint,but he managed to sucessfully re-join them well enough to not have any leakage ,and get the thing fired up again....he also said he has used the same method to repair brake lines in a pinch on their trucks they use around the bog--he claims it is no coincidence that a 1/4" brake line fits perfectly over a 3/16" one,and a 5/16" one fits perfect over a 1/4",and ditto for 3/8 to 5/16" ones...claims he has brazed a good many together that way,and has yet to have one fail...not sure I'd trust that on a road driven vehicle,but I guess its no worse than having rotted lines that may fail at any moment...or using compression fittings!...................................................................................................I doubt I could patch my lines that way because the worst rusty areas are right at the injector,on a sharp "curved" section.................................................................................................So far I guess my lines aren't leaking,been driving it 10 miles a day and haven't had to get towed home ..YET!..I mistook brake fluid leaking out of the master cylinders rear port,onto the injector line and a nearby wiring harness that allowed a lot of fluid to accumulate in the plastic spiral wrapping stuff ,it wasnt the line leaking like I thought--but it sure looks like it could be leaking any day now,its so rusted.....was just wondering if it were possible to limp home somehow by blocking off the failed line,or patch it some other way,in case I do get stranded!...

 

[82355]

Oops, yeah, I meant brazed.

Martin

 

[80' 427]

Am I stupid to suggest a compression fitting? You could just cut that line in half at the hole, slip on the coupling, then put it on and tighten. The size is 1/4 so that is common. If you don't like compression fittings you could use a Swagloc. Even NASA uses them.

 

[DEMON44]

all of the injection lines are exactly the same length. to maintain injection timing. if you change the length of one. you will notice it.

 

[diesel4me]

Yes,I read that too elsewhere,that the lines must all be equal length or it'll foul up the timing as far as firing the injector off at the right time--I also read somewhere the lines are about 6.5mm outside diameter and 2.5 mm inside,so if thats true,they are pretty thick walled...but the pits and rotted areas on mine are pretty deep too........................................................................................................I know compression fittings are NOT reccomended for use on things like brake lines because they could blow off or fail at pressures over 2000 psi,(though I have used them ,many times in a pinch ,and never had one fail,as well as many friends and mechanics!)...its one of those "might work,but do this at your own risk" deals...be better than walking home on some snowy night though,if a line failed ...are the "Swagloc" fittings rated for high pressures like brake and injector lines??...if so,I might have to buy some!...they wont be of much use if the line fails on a curved portion unfortunately,and thats where mine are the crispiest...

 

[DEMON44]

Injection pressure is over 2000psi. Even for idi engines. It's the hammering effect of the injection cycle that will be very bad for splicing of any sort. it's not recommended to repair injection lines.

I've used hundreds of swaglock fittings on miles of stainless tubing. Great for hydraulics. Still not good for injection lines.