Brake pipes...

[akku]

OK, here's a conundrum - what's the best material for brake pipes...

My synopsis of opinions garnered is this...

1. mild steel. Its like OE. It rusts. Its hard to form without a proper tool.

2. Copper. Its easy to form, its cheap, its easy to flare, but it apparently work hardens and snaps in service. Its illegal to use in some countries, apparently.

3. Kunifer. Easy to form and flare, more expensive than copper but doesn't work harden. Unfortunately when I've previously thought i was using Kunifer I appear to have been using copper as its not as easy to get as I thought.

4. Stainless steel. hard to form and flare. Most flare sets won't work on it. Expensive. Doesn't rust. some suggestion that it can also fracture? Although I could have got this wrong.

5. Braided hose. easy to run wherever you want, but the fittings are expensive and not OE if you have to join it to OE bits. MOT man might shake his head at this one too.

What do you use?

Why?

[jrevillug]

Seems like a reasonable summation.

I used copper on my car because I had an Automec copper pipe kit sitting around when I needed to replace them. It's attached using the OE clips at something like 10" centres and it's been fine so far with no hint of work-hardening. I wouldn't be surprised if it people did have a problem with it though.

I'd prefer to use Kunifer though - best of all worlds IMO.

[akku]

I'm considering pre-formed stainless kit from the US, not as expensive as you may think (unless there is a raping on shipping) and I'd get the right unions. Last time I made brake lines for a yank car I spent bloomin' ages trying to get imperial unions.

[phillipm]

I generally use kunifer for everything, even though my set will flare stainless it's not really worth the extra expense and it still has a corrosion problem if you're screwing it into ally calipers.

[usedabused]

Try and get them from Canada cos the import duty's are cheaper.

[Ratdat]

I've heard about the possible work hardening of copper but I have never ever heard of it actually happening.

[akku]

Jan 2, 2012 17:40:28 GMT usedabused said:

Try and get them from Canada cos the import duty's are cheaper.

I'm sure all non EU duty rates are the same now.

[mk2cossie]

i use cupro nickel pipe at work, not sure if thats the same as kunifer though

really don't like to use copper pipe if i can avoid it though, as the fact its easy to bend makes it a pain when trying to squeeze it past things when fitting them

if you can get a preformed stainless kit, i'd be going for that i think ;D

[gasserjay]

I would use kunifer / copper nickel if it was me, but use a good
quality flaring tool and it will make the world of difference.

[jrevillug]

Jan 2, 2012 18:05:58 GMT mk2cossie said:

I use cupro nickel pipe at work, not sure if thats the same as kunifer though

I'm sure that Kunifer is a brand name for Cupronickel in the same way as Hoover is for Vacuum cleaners.

[ChasR]

Kunifer AFAIK is Cupronickel.

After dealing previously with work hardened copper lines on more than one occasion I would be tempted to search out for Kunifer.

How much do you need? The Stag came with some steel brake pipe in with the spares. Depending on how much I use when I drop the rear subframe (in theory it should be none since I changed the flexis only last summer) the roll can be yours . Most of the Stag's pipes are still steel albeit covered in grease.

[composimmonite]

Another option is the plastic coated steel used by some OE manufacturers. Very good rust resistance unless the plastic coating gets damaged.
Personally I have never had any problem flaring or bending steel pipe. To be fair though I now use copper or Kunifer. It depends on what to hand rather than a preference to one type or another. In the past I've broken cars where I'd previously fitted copper pipes and although still sound they were starting to show signs of deteriation whereas Kunifer seems to last forever so suppose that is my final recomendation

Paul h

[Dez]

yeah, id go kunifer (which is brand-name cupro-nickel as james says above) every single time.

my reasons for excluding the others are-

copper can and does work harden, you need to keep the distance between clips and mounts very short to prevent this- typically 6" or less. it does corrode up quite easily too, especially when you add salt, so you ideally need to keep it greased as well.

steel pipes are ok, as long as they're kept well greased to keep corrosion at bay.

i see little point in using stainless, its material properties don't lend too well to brake pipes really. it needs to have quite a short free-length between clips like copper does or it can crack through vibration, and more than anything its a real curse word to work with as its so stiff. lets face it, no pre-bend kit ever fits without a bit of tweaking, and i dread to think about having to do that on a stainess set.

as paul says above, plastic coated steel in OE applications tends to last well, but if youre shaping and flaring it yourself you are invariably going to mark/damage the coating, making it no better than mild steel.

i use kunifer as its soft enough to shape by hand or with a ring spanner but hard enough not to fold in on itself when doing tight/fiddly curves like copper or steel can, doesnt really need any corrosion protection (i give the unions a squirt of coppergrease to prevent em seizing, but thats more down to the steel unions than the kunifer pipe), it doesnt work harden, and doesnt need loads of extra clips adding to hold it down.

[akku]

cheers guys. I can get pre-bent "OE" kits as well, I presumed this to be regular mild steel.

[khimanimohiki]

could you have the preformed steel pipes powder coated?

[andyborris]

Rally Design sell Kunifer by the metre or try a truck spares place?

[DavidB]

Copper - cheap (6 quid for metres and metres), easy to bend and flare (using 10 flaring tool and a jar), lasts for years.

[workinprogress]

copper,,,and the reason why is simple,,,its the best material to use as its malleable,,,light,,,cheap and easy to get a good flare seal,,,it wont work harden and split like stainless and plastic coated mild steel will.

braided stainless is fine for flexi's but will weigh alot more than copper if your planning to do the whole car with it,,,not to mention the price!

[CIH]

Anybody got any links for premeade lines ? I did copper lines for my Silvia but they're pretty damn ugly, if functional.

[workinprogress]

spray them with plasticote whatever colour you want alot cheaper than using expensive materials,,,just make sure you don't get any paint internally