Okay guys,

I figured I would start a fuel line discussion as this is brought up to me near daily. This is not a war of who's stuff is better, but for the sake of information.

You may or may not have seen a recent question posted here.

Let's get to it. This applies to ALL fuel systems using aftermarket rubber type hoses. I don't know if this is in the right forum, but seeing how it was a 2nd gen guy asking, I thought I would post it here. The mods can feel free to move it where ever it should be.


I am asked literally daily why we Vulcan Diesel Performance no longer sells or uses the blue fuel line available in the aftermarket kits. The reason is because it will fail.

At one time, we did produce and sell kits with blue fuel line. There are 2 primary companies producing these products, and they vary only slightly in quality. What we found is that after a few years in service, the line would fail. Now, what defines a failure? I define a failure as any defect that would compromise the structural integrity of the hose and or it's liner. In other words, a leak would constituent a failure in most instances. In other cases, cracking, swelling and delamination are all types of failures and can lead to a leak.

Why is this important? It's just diesel fuel right? Well, it's a combustible fuel. And while the risk in liquid form is fairly low of fire or worse, that same fuel can burn violently if atomized. Not to mention fuel pumping continuously out of a bad hose onto a burning fire probably wold not b good either.

So, that leads us back to what the blue line is and how it should be used. The hose manufacturers primarily list this hose as a transfer type hose. Meaning it is for moving fluid from point A to point B. Also, it carries no makings making it legal for use on vehicles driven on the street. I know that guys will argue this point with me, but it is in the spec and I will try to get that posted up int he next few days. I am fishing tomorrow and you can guess what my priority is on that one.

So what are the failures and what causes them? Well, to be honest, it does not seem to matter what is runt through them, they all tend to fail within a few parameters. Here's the lowdown.

Heat. Most of the failures we see are aggravated by heat. This means hoses in the engine compartment, specifically from the filter hosing forward are the locations that typically leak.

Fuel Type. This seems easy enough right? It's diesel! Well, mostly anyway. There are many different formulations and additive packages around the country. Also, in many places, you are getting some Bio, even though it is NOT specified on the pump. Also, many guys are going to home made or commercial bio, filtered veg oil and are using other products as additives such as 2 stroke oil, mystery oils, ect. These ALL have a damaging effect on the hose. We have places in the country that high much higher rates of failures than others.

Pressure, Line Size and Manufacture. And finally, it's the actual use with whichever product that seems to be the key. While 3/8" hose seems to hold up better for both primary manufacturers, the 1/2" hose is marginally worse. The higher the holding pressure, the higher the hour count and even the weather conditions all effect the overall life of the hose.

So why is this blue stuff used?? I can only guess at that one. And I feel it's because it has a "performance" look. And I think people often compare the color to Aeroquip, but do not understand the quality component.

We have many feet of this blue stuff on hand. We will NOT install it on any vehicle that gets a fuel system installed. The same hose in these kits is the same hose that we used to sell and have had failures with in the past. Honestly, we use it as air line in the shop for running tools, ect. That is it's only real use.

I know sometimes this kind of discussion can lead to hurt feelings or bruised egos or whatever. But the point is not to say that you have junk for fuel line. It's to know what to look for and why it is happening. As you may have seen in the thread above, we still get the occasional call about a failed fuel line. In this case, it is far out of warranty, but I know we will provide the newer replacement product just to keep our customer satisfied. That thread is a direct representation as to why we will not sell or install any of that line. And you're fuel system provider will most likely warranty any failures you may encounter.

Now, the question is gonna get asked. Why do we sell those kits with the blue line inside? The answer is economics. We cannot throw in or charge more for the line we use. Nor do we have to carry the warranty on those parts. The reason we do swap it in the shop is that we warranty our install. And to have to eat labor over a failed fuel line is just stupid.

I'll try to get some technical info on that blue line for you guys to mull over. Please, I am not attacking anyone, let's keep it civil and to the specifics of this product.

Dave

 

why are what appears to be less harmful fuels more harmful to fuel lines

 

Good write up Dave,I did not install the blue line when I did mine fuel system because it did not have any writing on it that it was to be use for fuel.I was going to ship it to vulcan so they can add it to there pile,now I use it for garden hose.

 

I do not know. Since I am only to dissect the failures, I can only tell you what conditions we see that causes the higher rates.

I know that adding 2 stroke oil, Veg oil and some bio mixes are destroyers of these hoses. I wold guess that any natural compounds in the hoses break down over time as a petroleum like based product passes over them. Add heat, and it's a losing battle.

If you can get a good clean blend of diesel, you are far less likely to have issues. And as mentioned earlier, locations with temperature extremes seem to have higher failure rates as well. Again, just guessing, but I would think porosity might have a hand in here.

Dave

 

Tossin' 2 cent towards the pile...

So far both my vulcan Big Line Kit and the AirDog 150 kit both came with the Blue 1/2 Hose. Now as for 2 cycle oil usage I'm heading for 4 years of 2 cycle oil usage with no signs of failure on the chunk of Vulcan hose I've got or the AirDog hoses. Still good. I would say the 2 cycle oils are safe but the BioFuel because of the methanol and solvency I would say is you bigger cause.

Now as for the heat theory your right... The Vulcan hose running from the stock filter to the VP44 is start to show small hairline crack in the outer blue skin.

But so far both kits are performing excelent and keeping the fuel pressure stable and high! (16 WOT and 17.5 IDLE)

 

Good write up, and thanks for posting.
Recently I found the blue fuel line on my truck had totally turned to mush. The inside liner had swollen quite a bit so i was having low pressure issues. The outside was the consistency of soft wax when touched. I was amazed to find it still holding together since it fell apart in my hands. I run homebrew bio the majority of the time and i jnow for a fact that the bio contributed to the degradation of the line. Its pretty amazing what that stuff will do to certain materials.
I replaced it with some 1/2" biodiesel rated hose and its worked very well for me since then.

 

So how about a list of the alternatives here.

 

so what exactly is the best type of line to be running on these trucks

 

Just a note. So far, the highest failure rates we have seen are with 2 stroke oil.

Again, none of this was to say that everyone will have an issue. But rather, what issues arise under what conditions based on our experience selling 10's of thousands of feet of hose.

Dave

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We carry our own lines that are compatible with diesel, bio and veg oil. To that end, we haven't had any failures with the guys running 2 stroke oils to date. In fact, we sell to some of the veg oil conversion companies as well. So, we still go through tons of hose! And we are carrying 4 sizes the last time I looked at the rack.

The stuff we have is black in color and a bit heavier wall. But it has taken some time to find what works for us.

We can still provide the blue line to the market. We get calls for it all the time. However, it will not be a warrantable product from us.

Dave

 

I installed high pressure fuel line from my factory fuel filter to the vp44 all other fuel line is factory issue.