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Author Topic: copper brake lines  (Read 6485 times)

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Offline cobra

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copper brake lines
« on: March 16, 2012, 08:32:54 AM »
Hi i want to make up two new copper brake lines, the ones that run from the caliper to the brake pipe,can anyone tell me the size of the male and female connectors on the copper tube, and someone who supplies them, i have tried david silver but no joy. this is for a twin disc conversion on a 750 f1
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Offline Bodi

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Re: copper brake lines
« Reply #1 on: March 16, 2012, 12:28:57 PM »
Don't use copper for brake lines. Copper will harden and crack open.
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Offline Stev-o

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Re: copper brake lines
« Reply #2 on: March 16, 2012, 03:36:43 PM »
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Offline Bodi

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Re: copper brake lines
« Reply #3 on: March 16, 2012, 03:45:42 PM »
The question was about copper, and using pure copper "refrigeration coil" type tubing for brake lines is suicidal. Obviously there are alloys made for high pressure work that are excellent for brake lines.
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Offline Gordon

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Re: copper brake lines
« Reply #4 on: March 16, 2012, 03:51:17 PM »
Quote from: Bodi on March 16, 2012, 03:45:42 PM
The question was about copper, and using pure copper "refrigeration coil" type tubing for brake lines is suicidal. Obviously there are alloys made for high pressure work that are excellent for brake lines.

+1

Equating copper tubing with a copper alloy is like saying iron and steel are the same thing. 
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Offline thep1pe

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Re: copper brake lines
« Reply #5 on: March 16, 2012, 07:29:23 PM »
In the UK we use brake piping called Kunifer. It's a copper nickle mix and is corrosion proof. Use it myself with a brake pipe forming tool. If you want you can get a NOS pipe from CSMNL.
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Offline LesterPiglet

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Re: copper brake lines
« Reply #6 on: March 16, 2012, 08:15:43 PM »
Quote from: rotortiller on March 16, 2012, 05:39:35 PM
Quote
All aluminum is not the same but they generally call it aluminum.

No, they call it aluminium. :p
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Offline Bodi

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Re: copper brake lines
« Reply #7 on: March 16, 2012, 09:33:21 PM »
Yes, people have used annealed copper tube for brake lines but that doesn't make it a good idea. It's fine for a few hundred psi, but at brakeline pressure it work hardens (you can call it metal fatigue - copper suffers from this severely) from the pressure expansion cycles. Once brittle it is prone to cracking open with the burst pressure slowly falling as the expansion cycles add up... then when you need your brakes more than usual one day in a panic stop the tube fails and the brakes aren't there. Poor plan.
Copper alloy brake line exists but it's rare and expensive compared to steel. Someone who knows about it and plans on using it would probably know where to get the required fittings as well.
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Offline cobra

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Re: copper brake lines
« Reply #8 on: March 17, 2012, 01:48:24 AM »
Hi i have a length of kunfer brake pipe to make the pipes with, my question was, does anyone know the size of the unions that go on either end, and a supplier, the pipe i have was left over from my Cobra kit car build, so i know its suitable for the job.
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Online bryanj

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Re: copper brake lines
« Reply #9 on: March 17, 2012, 01:57:25 AM »
They are m10 BUT there are two different thread pitches on m10 and the one that fits into the flexible needs the  end two threads removing and onlt an Op 1 flare to seat.

There is copper brake pipe made and it is safe to use but it is sold as BRAKE PIPE
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Offline cookindaddy

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Re: copper brake lines
« Reply #10 on: March 17, 2012, 03:55:15 AM »
In the US, copper-nickel brake line and the fittings can be obtained at http://www.cunifer.com/
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Offline Bodi

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Re: copper brake lines
« Reply #11 on: March 17, 2012, 04:54:21 AM »
That is a few hundred. Brake line pressure can get to 2000 psi. Thanks for the help.
Regardless, he has proper brakeline tubing. The fittings should be no problem but as described there are a couple of thread pitches used.
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Offline Bailgang

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Re: copper brake lines
« Reply #12 on: March 17, 2012, 05:43:44 AM »
Don't quote me on this but the way I understand it the reason pure copper tubing is a dangerous idea for use as a brake line is because of a reaction that takes place between the brake fluid and the copper. It's not that the copper work hardens due to brake pressure itself but instead because of some chemical reaction taking place between the brake fluid and the copper which makes the copper tend to be very brittle and unable to contain high pressure. It was from an article I read many years ago so I have no link to verify that info but apparently adding nickel to the copper resolves that issue. Years ago when I had my 65 GTO there was a Pontiac site I went to and 1 of the members was from a Scandinavian country and this same topic popped up and everyone on the site thought he too was nuts for using copper brake line but that member informed us that it was common practice where he lived to replace all steel brake lines, especially on American made cars with the copper brake line due to it's corrosion resistance. They obviously must have been using the copper nickel alloy brake line.
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Offline wrenchmuch

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copper brake lines
« Reply #13 on: March 17, 2012, 06:37:25 AM »
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Offline wrenchmuch

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copper brake lines
« Reply #14 on: March 17, 2012, 06:38:56 AM »
What appearance does Kunifer have.
Does it look like copper?
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Offline crazypj

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Re: copper brake lines
« Reply #15 on: March 17, 2012, 08:51:16 AM »
Quote from: cookindaddy on March 17, 2012, 03:55:15 AM
In the US, copper-nickel brake line and the fittings can be obtained at http://www.cunifer.com/

Thanks for link, I now have it bookmarked
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Offline cobra

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Re: copper brake lines
« Reply #16 on: March 17, 2012, 08:51:51 AM »
Yes. same colour and and bends easy, but if you bend it too many times it goes ridged.
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Offline 754

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Re: copper brake lines
« Reply #17 on: March 17, 2012, 09:04:16 AM »
 goes ridgid = work hardening

make them out of steel, then plate them, if you cant find cu-ni
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Offline LesterPiglet

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Re: copper brake lines
« Reply #18 on: March 17, 2012, 09:07:31 AM »
Quote from: 754 on March 17, 2012, 09:04:16 AM
goes ridgid = work hardening

make them out of steel, then plate them, if you cant find cu-ni
Rigid.   :P
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'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


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Offline tomkimberly

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Re: copper brake lines
« Reply #19 on: March 17, 2012, 06:55:57 PM »
I would go flex, so much easier to deal with and Z1 has every thing you would need.

Tom
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Offline 754

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Re: copper brake lines
« Reply #20 on: March 17, 2012, 09:20:32 PM »
 Are you talking from caliper to the splitter in rigid tubing ??..if so..not gonna do it !
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It's All part of the ADVENTURE...

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Offline cobra

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Re: copper brake lines
« Reply #21 on: March 18, 2012, 01:13:50 AM »
No, from caliper to flexible,
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Offline Don R

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Re: copper brake lines
« Reply #22 on: March 18, 2012, 08:38:51 AM »
Alex, I'll take honda brake fitting sizes for $100.  What is 10mm x 1.25.
 I haven't had much luck at the auto part stores. Not sure where to buy just the fittings.
« Last Edit: March 18, 2012, 08:41:43 AM by Don R »
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Offline crazypj

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Re: copper brake lines
« Reply #23 on: March 18, 2012, 01:02:36 PM »
10 is diameter in millimeters
1.25 is thread pitch in millimeters
Wrong pitch will mess up caliper, wrong diameter (inch size) could blow out and kill you (when brakes fail)
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Offline tomkimberly

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Re: copper brake lines
« Reply #24 on: March 18, 2012, 01:26:21 PM »
You do know there is a search function here, right?  Look for a thread I started about going flex to the caliper on one of my 350f's. It has pictures and part numbers too.

Tom

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