I'm considering using cunifer (copper nickel) lines for fuel. Great stuff to work with, did a entire brake system with it. Now I want to redo the fuel lines. Is there any truth to copper spoiling gasoline through some catalyst reaction? Cunifer is still mostly copper and not sure whether the spoiling of fuel is truth or rumor.
Are copper lines pressure rated? I'm far more concerned with copper in your brake system than in your fuel system.
A mechanic once told me of a problem he was having trying to find the source of a brake leak. The owner was having to add fluid regularly...
They couldn't find a leak anywhere...
They finally realized that the copper lines that the owner recently put on were "swelling" and slowly increasing the capacity of the system 
I don't know what type of copper lines they were and how that relates to copper/nickle, just an interesting story I thought about when I read this....
Copper and Cunifer are not the same. "They Say" not to use pure copper lines in automotive applications because they can become brittle. Brittle leads to cracks, leads to leaks, leads to fires, which are considered A Bad Thing. CuNiFer is an alloy of Copper, Nickle and Iron and is what the English use for brake/fuel applications and is generally considered OK to use. If you trust the English.
I don't know aout that stuff, but copper lines are known to crack, espacially at the fittings.
Copper used to be used for fuel lines sometimes but never for brakes.
They were standard equipment on all Volkswagens from 1938-1960.
Dr Hess has got it - Cunifer is not "copper," it's an alloy and is intended for brake lines. It's fine to use for fuel as well:
"Cunifer is seamless, copper nickel alloy DOT approved brake line used for OEM and replacement brake lines, fuel lines, power steering and cooling lines."
from here:
http://store.fedhillusa.com/cuniferbrakeandhydline.aspx
It is true that copper catalyzes the aging of fuel. I would not use it. All major fuel system component manufacturers reccomend not to use it (and I know at least two specifically do not allow its use if you want to qualify for the warranty). Is there anything wrong with good old fashioned rubber fuel line?
You are dicussing two entirely different metals. copper fuel/brake lines are not copper like you use for plumbing. There are fuel/brake rated "copper" lines.
Jack
stumpmj wrote: It is true that copper catalyzes the aging of fuel. I would not use it. All major fuel system component manufacturers reccomend not to use it (and I know at least two specifically do not allow its use if you want to qualify for the warranty). Is there anything wrong with good old fashioned rubber fuel line?
the car in question has hard lines on it. I could do steel, but then i would have to do it again in 10 years. I could do stainless, but that would really suck. I did brake lines in stainless before, but it was super tedious due to it work hardening. I could only imagine the pain of using larger diameter tubing fuel requires.
dculberson wrote: Dr Hess has got it - Cunifer is not "copper," it's an alloy and is intended for brake lines. It's fine to use for fuel as well: "Cunifer is seamless, copper nickel alloy DOT approved brake line used for OEM and replacement brake lines, fuel lines, power steering and cooling lines." from here: http://store.fedhillusa.com/cuniferbrakeandhydline.aspx
Thanks. Learned something.
dculberson wrote: Dr Hess has got it - Cunifer is not "copper," it's an alloy and is intended for brake lines. It's fine to use for fuel as well: "Cunifer is seamless, copper nickel alloy DOT approved brake line used for OEM and replacement brake lines, fuel lines, power steering and cooling lines." from here: http://store.fedhillusa.com/cuniferbrakeandhydline.aspx
the problem is i got it from them. It is probably okay for diesel, but it might be a different issue with gasoline.
I tried using conifer fuel lines, but the injectors kept getting clogged with pinebark.
PeteWW wrote: I tried using conifer fuel lines, but the injectors kept getting clogged with pinebark.
ouch.
You should have used the cones that only open up in a fire.
What about braided lines to replace the hard lines?
Gearhead_42 wrote: What about braided lines to replace the hard lines?
didn't think of that. I don't know what the gas tank end looks like, but where do I get fitting to hook up to a standard fuel rail quick disconnect? It's for a chrysler.
How nasty is the braid rubbing through stuff problem even with sheetmetal mounting clamps holding them in place. Don't want to create another rust problem while solving another.
problem with braided lines.. if they rub against something, they will saw through it in time
I dunno about chrysler stuff, as I try very hard to avoid chrysler products, but Doorman, I think, carries connectors for various EFI systems. I used some of their products (purchased at O'Reilley's) to hook my Ford EFI fuel pump up to my Toyota.
Yeah, with stainless braided lines, you have to worry about what they are next to, not the lines. But, as long as you have it all clamped/tied down well, you won't have a problem. Russell lines are the best. Hardest to work with too. I replaced all the oil lines on my Harley with Russell stainless braided, and I use it for the EFI lines on the Sportster too.
Being cheap and lazy, on my firetruck I replaced all the fuel lines with new steel brake lines, but I cleaned them off real well and covered them with heat shrink tubing before I actually installed them. I ran some bigger clear heat shrink over all the nuts and unions I could and shrank down on them back over the top of the tubing on each side to seal it all up. I had to remove one once, it wes still nice and new looking. They've been on there for years now, but the thing doesn't get driven much so it might not turn out to be such a good ideal in real-world cars.
You can heat shrink cover braided too and not worry about the hose chafing other things or suffering from internal dirt abrasion.
oldopelguy wrote: Being cheap and lazy, on my firetruck I replaced all the fuel lines with new steel brake lines, but I cleaned them off real well and covered them with heat shrink tubing before I actually installed them. I ran some bigger clear heat shrink over all the nuts and unions I could and shrank down on them back over the top of the tubing on each side to seal it all up. I had to remove one once, it wes still nice and new looking. They've been on there for years now, but the thing doesn't get driven much so it might not turn out to be such a good ideal in real-world cars. You can heat shrink cover braided too and not worry about the hose chafing other things or suffering from internal dirt abrasion.
Thats a pretty good idea. I heat shrunk over some goodridge lines i got for a vw. The last thing i wanted was for them to saw or degrade them with dirt exposure. Didn't think of doing the it for the hard lines. Gonna look into that.
But still, is there a consensus that copper is bad for gas? How fast does it spoil it? Months, years, days?
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