Copper or stainless brake lines?


#1

Need to replace rear brake line on 1997 Acura CL. Looking over copper or stainless brake lines. Is there a preference as far as which one is easier to work with? Supposedly they now make “soft” stainless lines for easier bending. Not sure if that affects quality and endurance.


#2

pure copper is generally not recommended, as far as I know

stainless steel would be a better choice


#3

Are you making up your own? Why not go to a car parts store and get one pre-made?


#4

Plain copper tubing will not take the pressure of brake fluid. Wrapped brazed steel is the norm for brake lines. These come bare or coated in polymer wrap for corrosion protection. This will double-flare and bubble (ISO or single) flare very easily. Stainless tubing is harder to bend and double flare. It will be difficult with cheaper hand held tools. The good tools to double flare this stuff, is pretty pricey. I suggest the mild steel wrapped and brazed bare tube. Installing it will be much less painful.

If you don’t know what a double flare or bubble flare are, please look it up before you start making lines. Single flared brake line can fail and if the fitting calls for a bubble flare, a double will not seal.


#5

Are pre fab lines an option? that would be my choice.


#6

That’s what I’m talking about - match up the fittings and the overall length at the neighborhood Autozone/whatever.


#7

I thought about getting a pre-made line for this car, but I am also thinking of replacing the other brake lines as well. They seem OK, but where the fasteners keep them in place I can see rust spots as well. Seems over the 20+ years the constant vibration and weather is getting to these areas. I was thinking of making this a weekend job. It’s a second car and no rush.

I might take a second look at pre-made lines.


#8

The first set lasted 20 years. If the pre-made set lasts another 20 years, that would be good enough for me.


#9

You will not find copper at an auto parts place because you should not use it on autos. Use only genuine auto brake lines. You can find them in various lengths, with the correct end fittings, at many of the better parts places. If it’s a little too long you can bend it carefully.


#10

There’s a nickel-copper alloy version of brake line that’s available & ok to use in the USA from what I can tell. This subject has been discussed here before. As I recall there are some diy’er benefits to using the nickel copper version, but what they are … hmmmm … lol … I don’t recall.


#11

Maybe more bendable without kinking? I did not know there was a copper-content brake pipe. I was picturing copper as in my basement plumbing.


#12

Copper-nickel alloy is probably pretty tough stuff. I guess it is sort of like first people into metallurgy discovered the usefulness of copper, then even better when they added some tin to get bronze, then to add zinc to get brass.


#13

The copper -nickel brake lines are made for automotive use, are bendable by hand come in coils of different length. They have been used in Europe for years and are required on new cars in some Scandinavian countries.


#14

Correct.
Over here we call them copper pipes, but I think the correct term is cunnifer.
Some cars comes with them from factory, but when steel pipes are getting replaced, it will be with “copper”. They’ll last for the rest of the cars life.
You either buy them by the coil or a ready made set for the specific car. If you make them yourself, remember to buy the correct fittings as they have to be made of brass or aluminum.
They are very easy to flare and bend into shape without getting kinked.