With rearend stripped of all suspension and drive components (again) and the car minding its own business on the quick lift (which is much higher than than the stacked 4x4's I had under the frame last time) I figure maybe I should replace the fuel lines - 38 years is a pretty good run. I searched the threads but didn't find anything specific to this. So, I would like to ask for any guidance on the following areas:

Best source - I would like to avoid the issue I had with Classic Tube brake lines purchased 7 or 8 years ago where frankly none matched my originals to the point that I took them all out and had a replacement set made to match the originals. If someone has info but does not want to put it out publicly, please send a PM.

Potential pitfalls - Things like areas where it just becomes a PITA unless there's a trick to know, any unusual tools, etc.

Does the tank need to be fully dropped or can this be worked with it just partially down the 3 or 4 inches that can be gained loosening the straps.

Whatever else might be useful to know.

Thanks,

 

I just removed my fuel lines this weekend. Since I live in Europe I bought a copper-nickel lines and will bend them myself.
I have removed my fuel tank, which wasn't that hard, and it is much easier to work around the back of the car.
As for the rest of the lines the part around the rear frame is tight as he..!
I will swap those with Earls racing lines because with body on I couldn't squeeze and bend the lines as they should be around the frame!
I used rubber fuel lines but only temporarily as those are deemed unsafe for my taste!
Here is one picture of vapor line that is already done!

 

I know what you mean about the working around the frame cross members and side rails. I had to work a brake line through there - twice. Per my post, I do have all non fuel tank items out of the way so that opens it up a lot. I had the tank all the way out last fall. While getting it out was not bad, getting it back in was a pain. Being an 80 it is the larger tank and has a thick foam pad on top. It was very difficult to keep the pad in place and compress it enough to get the tank back in.

Do you have any concern about the rubber lines rubbing against metal and wearing through? I guess if that was a concern some spiral wire harness wrap could be use to protect it.

 

Yes I do have worries. That is why I'm putting these on there:
https://www.holley.com/products/plumbing_an_fittings_and_hose/earls_classic_hose_and_hose_ends/perform-o-flex_hose/parts/400060ER

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I concur with the strategy of using the CuNi lines instead of regular steel. They are MUCH easier to bend and form, so the difficult areas to fit should be a lot simpler. If you do that, you also need to invest in a simple line-tubing straightener. The CuNi lines are so easy to bend, they sometimes can do so simply under their own weight. This isn't any problem if you retain the fuel lines with all the clamps originally installed on your car. But, if a long run needs to be straight to look right, a simple use of the straightener before installation will solve than minor fault.

What I do not know is whether you need to use ethanol-free fuel, if you have CuNi fuel lines. I know that metals like aluminum or copper can be attacked by the ethanol over time. But will the same thing happen to a copper/nickel alloy? An article I read indicates that CuNi is especially resistant to oxidation when salt-water or acetic solutions are put through it.

 

I guess you have to go high value on these lines. I did not replace the original short rubber lines between the tank ports and the long lines when I had it out. I started to replace them with hose from local parts store. But that stuff was developing minor cracks just from me putting it on the metal lines. The 38 year old original hose was actually in better shape. So I opted to leave that on at that time.

 

Now that is a good question! I hope someone has an answer for it.

 

My guess would be ethanol is not an issue or there would be a lot of posts about failing CuNi fuel lines. Most of the concerns posted which I have seen focus on the copper side without considering that the alloys behave much differently than the metals in them. I wouldn't use copper brake lines, though they were still sold in the 70's. But there are plenty of 70% Copper / 30% Zinc (aka cartridge brass) fittings in brake systems. On the plus side, I know of one business which uses a lot of copper with ethanol - just hang out in the Appalachian Mountains. In fact, I did find one table listing corrosion resistance of CuNi to many chemical. It was listed as highly resistant to attack from beer and whiskey, among other things.

 

You could use the NiCad hard line with a 37 degree flare adapter to -6 flex line. I did a 68 C10 last winter with the NiCad for brake lines. It flared like butter.

 

I did my lines (supply and return) a few years ago while the rear suspension was out (and tank was out as well) so I'll give my $.02
Lines came from CC stock replacement steel lines, no real issues with the fit, came bent in half for shipping and I straightened out the loop somewhat before installing.
Made a special wrench to help get at a couple of the line clamp bolts that a regular socket / boxed wrench didn't work out on
Cut a cheap 1/2 socket in half and welded it to a thin metal strip


Fed the lines sideways from the drivers side up over the dogleg while my brother dealt with them out at the wheel-well so they didn't beat the paint to death. Had to massage them back into shape after they made that corner along the top of the frame.
My car is an auto with the removable trans x-member so it was out with the trans supported, I don't think it's doable without cutting the line on a welded x-member
On mine, the shoulder-belt bolt comes down on top of the frame where the line goes and it's tight, there is a loop in one of the lines that has to be positioned right, maybe your's doesn't have that
lines came with rubber caps on the ends, left them on and also taped them in place to make sure they stayed
Anyways, it does work with some screwing around
M

 

This sounds very much like a replay of getting in the brake line that runs from the prop valve to the rear splitter block. I didn't take the removable cross member out. I tried to get it out later for another issue. But it didn't seem to be able to drop out without hitting the brake and fuel lines. You can see this in the photo below.



On the other side it was hitting the brake line so I couldn't slide it to one side to slip past one set of lines without banging into the ones on the other side. Is the trick to take the clips off the lines first so they can move up and down with the cross member until it's in position? Another thing on this cross member is it is that getting the mounting bolts back into it after trying to remove it took a huge effort. I don't know if the original holes were not drilled precisely or of something is out of alignment frame wise. On the alignment issue, the only thing which happened since I bought the car new was when I rear ended an Impala (the Chevy version, not while driving on the African Savanna) in 1984. A pretty amazing outcome. I knocked off the Impala's bumper and crumpled a section of its trunk and one rear quarter panel and took out a tail light. The only damage to the vette was a few small paint fractures and a small crack underneath the front bumper behind the polyurethane section. I never fixed any of that. But, it was a hard hit and while driving a couple hundred miles up to my parents' home that evening it rained and for the first time I got some leakage through weather stripping on the t-tops. So maybe there is a little twist somewhere and the cross member loading when I tried to bolt it back in maybe telling me something.

All that aside, when doing the brake lines I opted to have a two piece line made to get through the cross member. I also had the issue of not easily getting to some of the line clamp bolts. I managed to find one offset box wrench which fit. So it's starting to sound like getting the fuel lines in will be like the brake line times 3. On the plus side, since these are fuel lines, cutting them and linking with hose or compression fittings would seem to be an option. As I've mentioned in other posts, this is an '80 and will never be a show car. I just want it fun to drive, looking good, and to run like a vette should.