Hey Guys I have my fuel bowl out and put all new O-rings on, my question
the fuel lines from the fuel pump were cracked so I am replacing them. the ones
on the truck were blue, but the one that I got from the part store are black....do they
have to be blue lines? The hose I got are fuel injection lines.

 

Don't have to be blue but does have to be diesel rated

 

Those are likely not diesel rated and will likely leak (eventually) cause they can't take the heat.... But someone more experienced may contradict me.... Richard

 

I got my hose from Napa and it is black. But I made sure and asked for high pressure diesel rated hose. This hose is also rated for bio-diesel. Like stated above, make sure its is diesel rated and not gas fuel injection hose.

 

As long as it is diesel rated you are fine.

 

That guys for the quick reply. I checked and the line is r30 rated for diesel.
I can' t belive how hard setting some of those O-rings are.

 

Fuel Injection Hose (Black cover) can have various ratings. The most common are:
30R7 - 50psi
30R9 - 100 psi
30R10 - 100 psi submersible

The problem with these standard hoses are they do not have a very high temperature rating and will rapidly degrade in the valley of the 7.3 from the radiated cylinder heat.

Blue colored fuel line will always have a higher heat rating than any black colored hose. The blue colored hose that is offered at the dealers and on my site is 300 psi working pressure, 1200 psi burst with a 300 degree temperature rating.

Even this hose will break down over time but it will take many miles compared to the standard fuel injection hose. Also keep in mind when using hose clamps of the worm-gear style, will quickly cause the outer layer of hose to extrude through the slots of the gear holes. You should only use a fuel injection style of clamp when exposed to the heat of the valley as these have a smooth interior and are built similar to a t-bolt clamp.

When tightening a clamp on a hose, most will over-tighten them. The exterior diameter of the clamp should be the same as the outer diameter of the surrounding hose and no tighter, in other words, if you ran your thumb across the clamp, you should not feel the hose bulging out on either side of it. Over-tightening clamps will cause damage to the interior lining of the hose at the ends and the hose will prematurely crack and leak.

 

Hey diesel O-rings thanks for the great info. I know I have to pull my fuel bowl off to do some other mods early next year so I will go to your site and get the right stuff. my truck had blue lines, but it had the regular clamps that were probably tbe wrong ones.