Sierra based Cabrio Brakes

[bryannewell]

Hi folks
After replacing leaky Master Cylinder and then attempting to bleed the Brakes I now need to renew wheel cylinders and as a consequence of that now the short
lengths of brake pipes that fit to them
I have 3/16" copper pipe but what has come off is a different material(Harder but not steel) can anyone shed any light on what this is likely to be? and would it be a problem to replace with normal copper?
Regards
Bryan

[philcoyle]

Re: Sierra based Cabrio Brakes

It is most likely Kunifer Pipe, it's used a lot in car restoration. The copper pipe is easier to form but I like the strength and rigidity of the Kunifer.
You can form it with your brake pipe making kit just make sure it's clamped in the formers really tight, and have 3 shredded wheat for brekkie.

[cameronfurnival]

Re: Sierra based Cabrio Brakes

Yep - almost definitely Copper is very soft Kunifer is a mis of copper nickel and iron (hence ku (Cu) Ni Fe) Mostly copper but with other metals for strength etc. I would always recommend a pipe bender (even a cheap one will do) rather than trying to bend by hand - it always goes well till the last second! - and get a proper pipe cutter too - a couple of quid. It is of course quite ok to replace the pipes with plain old copper, much easier to form but again use a pipe bender for neatness and avoiding it kinking.

[greyV8pete]

Re: Sierra based Cabrio Brakes

There has been a lot of discussion recently about kunifer on the Madabout forum. Well worth a read. Biggest problem with pure copper is that it work hardens (so becomes more brittle) with age / vibration which is why kunifer was developed. Peter.

[bryannewell]

Re: Sierra based Cabrio Brakes

Thanks guys
That sounds like it
As said I do have copper left over from a previous Roadster rebuild but when I went to form some flares I broke the Flaring tool Die(teach me to buy cheap!!)
Looking into some pre made stainless flexibles at the mo
Will post what I decide to do
Regards
Bryan

[bryannewell]

Re: Sierra based Cabrio Brakes

Just to follow up
Decided to go with stainless flexibles after finding a website for a company called HEL
Great site where you can customise to suit,picking length,adding end fittings,sleeves,bobbins etc even a large range of coloured finishes all at the touch of a
button with visual display where you can see it go together as you choose
Very pleased with the result
Bryan

[greyV8pete]

Re: Sierra based Cabrio Brakes

Hi Bryan. Off topic completely but I have sent you a PM about your ignition switch - re Pitstop European Tour article. Peter.