Fuel, Brake and Trans Cooler lines replacement questions

[msg]

I am planning to replace the lines as I rebuild and there are some questions I have on the types and sizes of the lines to use.

Types to use?
Stainless steel was the first thought but others have suggested Nickel/Copper instead. Is this type of line ok for all 3 needs that I have, or is stainless steel better for fuel and transmission fluid?

Bend or buy pre bent?
I have a bending tool and thought to buy the right types and sizes of lines in a coil and shape them as I need to. I have the old lines to match up but I am putting in a L31 engine vs the old 350 from 1975 that was in there thats not in good shape. Because of the new engine and running an electric fuel pump there will be differences Ill have to figure out, but I was thinking to buy in coil format and size things up as I go.

Sizes for each line that I need
Is the measurement supposed to be outer or inner diameter?

Brake Lines
Ive been measuring the Brake lines and from the master cylinder to the front discs are measuring outer diameter .250 in on the caliper tool but the lines to the rear drums are reading .206 in.

Fuel line
The measurement I have on the old fuel line is .3245 in

Trans line
The measurement I have on the old trans line is .3195 in

[LostMy65]

Updates?

[msg]

I have so far only redone the brake lines and from a separate thread I started found out that I was missing a proportioning valve for many years in my conversion setup.

http://67-72chevytrucks.com/vboard/s...d.php?t=798604


I went with cunifer (nickel copper) lines, I hope it lasts. I tried out the rental tool for flaring the lines and didnt have much luck. I had to buy a tool off Amazon and it worked great. Expensive though. Here is a link to that thread.

http://67-72chevytrucks.com/vboard/s...d.php?t=798468


So far I havent gotten to the gas tank and the transmission lines. On the fuel lines I have been told by a tech at Holley that cunifer is fine for fuel. Ive also been told by others that they also have used it. Whether or not its proven to be compatible with fuel over time I dont know. I am not sure there is any scientific data on it's compatibility, would be nice to know.

[The Rocknrod]

High performance manufacturers such as Aston Martin, Porsche, Volvo and Audi have chosen to install copper-nickel alloy over all other materials including stainless steel.

[msg]

I had also read that for brakes on this website, of course its a copper promoted organization.

https://www.copper.org/applications/...ube/brake.html

I used it for the brakes and it was simple to work with. I am pretty sure thats what Im going to use for the rest. I sent a message to that organization and asked for some information on fuel and transmission as well. Ill post what I get.

[88Stanger]

I will post what i used, subject to preference.
On "69 LS C10:
Brake lines - Nickel/Copper lines
Fuel lines - I used aluminum 3/8" to -6 AN Fittings and Steel Braided lines
Tranny Lines - I used PTFE line and fittings

On "66 Gen 1 383 stroker C10:
Brake lines - Nickle/Copper Lines
Fuel Lines - all -6 AN Fittings and -6 PTFE lines
Tranny lines - Not needed = 4-Speed

Not sure this helps, but i will say this, if you are going to want to drag race the truck, there is a limit on feet of rubber hose you can run, just as a heads up.

Good Luck

[msg]

Late thanks for that info 88Stanger, if I ever get this truck back together I wont be racing but will be driving reeeeaaall sloooow until I make sure the brakes I redid actually work. Never touched brakes before so this will be either a wow I actually did it or a I never should have done it myself moment.

I did get a reply from the site I mentioned. Although the contact I had focused on the brake application and not fuel here is what they said

My Question
Hi, Ive read an article on your site about brake lines being safe for copper nickel/ cunifer lines. Is there any data or information that shows that copper nickel/cunifer is ok for fuel and transmission lines? I was going to replace the lines on my truck and was told that copper might not be safe or compatible with copper. Thanks.

The Reply
"Copper nickel brake tube is almost always used on off road heavy equipment, not to be confused with copper tube. Please go to the CDA web site and type "copper nickel broke tube" in the search box upper right, and see, " Applications: Automotive - Copper-Nickel Automotive Vehicle Brake ... https://www.copper.org/applications/...ube/brake.html It also identified copper-nickel alloy C70600 tube as outstandingly superior to conventional steel brake line tubing in laboratory salt-spray-exposure burst tests. There are other supporting technical papers listed there. "



I saw on their site here some good info on corrosion

https://www.copper.org/applications/...oklet.html#2.3

Table 18 rates corrosion resistance to different agents. Petrol is top rated with a 1. So is beer, good to know. So I will be going with copper nickel all around.

[The Rocknrod]

I dont know, I used steel for the fuel line only because when I ran it I didnt know for sure at the time. I have seen people on here (and other places) use it for gas though. I'm quite sure there would be all kinds of online presence about that if it didnt work.

[msg]

So on the fuel line size, what size cunifer should I be running? The mightly might electric fuel pump will be feeding a quadrajet on an L31 Vortec. The previous lines look like they are 3/8".

I had emailed the tech at Holley and the reply I got was this.

"as far as what size lines to use, that depends on your horsepower.

-4 - 400hp
-6- 600hp
-8- 800hp
-10- 1000hp"

[The Rocknrod]

I'm using a 3/8" fuel line (steel). I asked the question of using a 5/16" fuel in the past (for a V8) and was it was looked own upon heavily by most.

[Corts60]

We use copper fuel lines in the marine industry a lot. The only time there is ever an issue is when copper and aluminum touch each other. They need to be separated to prevent a galvanic cell from occurring (corrosion). So, say you want to attach your copper fuel line to an aluminum tank, we would install a stainless fitting in between to act as a barrier to help prevent corrosion.

Copper works great with both gas and diesel.