The Stovebolt Site Forums The Shop Area Driveline Leaking brand new nickel copper brake lines...now what?

My son and I just finished up new nickel copper brake lines on his 51 1/2-ton with a new dual MC from Classic. It looks beautiful but every joint leaks between the new flare nut and the line.

I've tightened until i'm scared i'll strip the treads on something. ALL parts are new. The line and the flare nuts came from Jegs and a few of the brass fittings came from a FLAPS.

Now what?....Anyone else have this problem?

It sounds like a flare mismatch between the lines & the fittings. (To where the lines and fittings wouldn't seat and seal properly)

Brad

Not really enough info to help you out Ken. Do you literally
mean, "every joint leaks.."? And a full description of the
way you made up the lines would help.

1. Was the line pre-made or just the line and fittings that you
had to flare your self, (did you use a double flare)?
2. You didn't use pluming tape on the fittings did you?
3. Did you use all new brass inverted flare fittings?

dg

I used the nickel/copper lines on my 47GMC. Purchased a 25 foot roll and did all my own DOUBLE FLAIRS. As you, I has a few leakers. To seal it up I loosened the fitting wiggled the line around a bit and re-tightened. This reseated the double flair. The fitting will take quite a bit of torque. With a back-up wrench and a flair nut wrench I put a pretty good arm on it. Never stripped a fitting. Do not used any Teflon tape. The brake fluid on the threads helped as a lube to get a little more torque. None have leaked since.

From experience I can tell you that over forming double flairs will keep them from sealing.
Nickel copper is easier to form than steel, so if you really clamp down on the second flair there is no give left for it to conform to the fitting (unlike a single flair that will conform to anything).
When you make the double flair in nickel copper, form the first stage nice and tight then stop a little short on forming the second flair. The nut will pull it in and seal easily.
In my case a new hydraulic flairing tool made it very easy to squeeze the second stage too much.

I also find it helps to grease the back side of the flare and inside the nut so they don't bind while tightening. A little grease on the threads doesn't hurt either, or one or two loops of teflon tape on the threads for lubrication only.

You may want to look at the inside flare of the fittings, over time the get distorted and won't seal no matter you do to the tubing.

Joe

I have used nickel copper, or nickel plated copper lines for fuel, but I was taught and always told that steel lines are the right brake line material. I was taught that nickel copper is too soft for brake lines and can burst under pressure. Nickel copper lines are mostly used for plumbing lines in commercial buildings and residences.
No trying to criticize, or scare anyone, but it's a surprise to me.

What is referred to as Nickel Copper lines is actually an alloy of Cu (copper) Ni (n1ckel) and Fe (iron).
In engineering circles it is called CuNiFe pronounced as it is spelled.
Nothing like copper tubing that does not have the burst strength to work in a hydraulic braking system.

I used a hydraulic flaring tool. What you say makes sense Jim Sears. Next time I will be a little more careful on the second crimp.
I do believe that quite a few European cars use CuNiFe.
And yes, a little brake fluid on the threads does not hurt, but shouldn't be needed.

I've used the Nickel Copper on my Dodge Dakota with its Bubble flares and on my 1-ton Stovebolt GMC with double flares and the nickel copper works like a charm, I had no leaks which speaks entirely to the forgiveness of the material and not my skills. My flaring skills are not so good, but I recommend using brake fluid on your flaring anvil tool while you are making your flares, and then cranking the fittings really tight.

I have found that sometimes removing the fitting, then tightening it down again (a few times) helps to shape the flare to the fitting better.

Nicop tubing can be over flared very easily. You only tighten the second flare until it stops on light force and you see that its inverted, its not like steel where you crank it down hard. If you use the same force as steel then it has a tendency to fracture and split not visible to the eye,

These are all greats posts. Thanks so much.

To follow up with Denny...Yes, every joint leaked. I bought an inexpensive vacuum bleeder and I could not even get it to pull the fluid through the lines because it was sucking in so much air.

This is all 100% brand new material. I bought the 25' coil from Jegs along with the matching flare nut ends that are coated black. All the brass is new and came from my FLAPS along with their loner double flare tool. I guess we could have two different flares; one for the tool and a different one on the fittings. I just guessed that all automotive was the same. I guess I'll have to check that out.

We haven't worked on it in a week but I was going to try ctheusa's technique. I had read on other posts that you needed to do the loosen/re-tighten technique with stainless so I thought it wouldn't hurt to try.

This is the first time we have tried this so we could have over stretched the second flare on the double flare set-up. Having it make up during installation makes sense also.

We did not use any plumbing tape etc on anything.

To all those who have posted...thank you very much. We have learned so much from other peoples projects that it has really helped ours. I hope we can pay it forward soon.

Can you take close-up pictures of your flares and fittings for us? Maybe the fittings are wrong for the truck? There are different depths on the fittings, etc. I always wondered why in the world that fittings and flares were not standardized. When I was doing the Dakota I had not ever heard of a metric bubble flare. The local Napa had nothing for it (they've gone way down from what they used to be but thats another story). So I had to order the special tool and the ends over the Internet.

There actually is a standardization, Double Flare are always Standard dimension, and Bubble Flare are always Metric. The fittings are noticeably different where they seat on their respective flare, and as mentioned, the threads are different as well.
That said, I have come across a hybrid flare, that is a combination of both a double and bubble flare. I've seen them mostly on FWD GM products, but have also seen them of Ford trucks.