12 replies to this topic

[redminijim]

Hi all, I am doing up my pick up and upgrading the brakes . I am fitting a new brake master cylinder (yellow tag I think) new compensator and having disc brakes .
My questions are 1: is this system classed as a single line rear split system , only one pipe needed front to rear and it Goes into a t piece on rear subframe ?

2:does anyone know of measurements for pipes as the pickup needs a longer front to rear pipe if I remember ? And / or can I just buy a kit already made. I have seen one kit but it's for a drum brake set up so I suppose the pipes are incorrect . Thanks in advance and hopefully it all made sense. Cheers, Jim .

[mk1leg]

get yourself a flairing tool and some pipe and connectors and make them to measurer

[tiger99]

There is no such thing as a "single line rear split system". Yours is a dual circuit front/rear split with Pressure Reducing Valve. The master cylinder has two dissimilar ports with metric threads and the PRV would also seem to be metric, everything else being UNF. There is one line from the PRV to a T piece on the rear subframe.

 

Be sure to insist on Cunifer (cupro-nickel) pipe, not copper, which despite being sold widely in the UK is illegal almost everywhere else because it has very poor fatigue properties and is regarded as unsafe.

[59 Speed]

get yourself a flairing tool and some pipe and connectors and make them to measurer

+ 1

Don't forget to get a pipe bender and make sure you use kunifer NOT copper pipe.

Then have a good practice, there's how to's and vids on the internet.

[Dusky]

I wonder how long copper lasts.

[Steve220]

I wonder how long copper lasts.

Not as long as cupronickel. Copper's usually used as its soft and easy to use. Personally I'd paint them to try and prevent corrosion.

[redminijim]

Thank you for advice peeps , much appreciated.

[spraybeater]

Check DSN classics site! they do some nice cupronickel made up sets,

I bought some and was well impressed with them and I used to make up

hundreds of brake pipes over the years but always  had access to proper 

pipe flaring tool now find it cheaper to buy made up than buy a proper flaring

tool.

[Dusky]

 

I wonder how long copper lasts.

Not as long as cupronickel. Copper's usually used as its soft and easy to use. Personally I'd paint them to try and prevent corrosion.

 

But 'not a slong' is so vague.

If cupro nickle last 1000 years it'd be fine for copper to last 10% of that. I wonder if someone has some actual data on this?

As I do know that there are american cars wich came out of factory with copper brake lines, and i wonder how long those did last

[Alex_B]

 

I wonder how long copper lasts.

Not as long as cupronickel. Copper's usually used as its soft and easy to use. Personally I'd paint them to try and prevent corrosion.
 

But 'not a slong' is so vague.
If cupro nickle last 1000 years it'd be fine for copper to last 10% of that. I wonder if someone has some actual data on this?
As I do know that there are american cars wich came out of factory with copper brake lines, and i wonder how long those did last

The main issue isn't with corrosion of the copper pipe it's the fatigue life. As the pipe is pressure cycled through use of the brakes the inside surface hardens, it then splits in the same way if you bend a copper pipe back and fourth until it work hardens and crack. Cunifer has a much better fatigue life and doesn't work harden so readily.

Edited by Alex_B, 28 August 2016 - 10:46 AM.

[Steve220]

Check DSN classics site! they do some nice cupronickel made up sets,
I bought some and was well impressed with them and I used to make up
hundreds of brake pipes over the years but always  had access to proper 
pipe flaring tool now find it cheaper to buy made up than buy a proper flaring
tool.

That's useful to know! Wanted some made up ones as I don't trust myself enough to do a good enough job. Especially on something as important as brakes!

[Dusky]

 

 

 

 

But 'not a slong' is so vague.
If cupro nickle last 1000 years it'd be fine for copper to last 10% of that. I wonder if someone has some actual data on this?
As I do know that there are american cars wich came out of factory with copper brake lines, and i wonder how long those did last

The main issue isn't with corrosion of the copper pipe it's the fatigue life. As the pipe is pressure cycled through use of the brakes the inside surface hardens, it then splits in the same way if you bend a copper pipe back and fourth until it work hardens and crack. Cunifer has a much better fatigue life and doesn't work harden so readily.

 

But its still so vague  
Im sure, someone must have tested this once?

[tiger99]

Yes. Google for cupro-nickel brake pipe and you will find that the Copper Development Association have articles about the fatigue life. But please understand that it is NOT life in years but strain cycles, which result from flexing due to vibration, and much more importantly, pressure cycles as the brakes are used. In an aggressively driven car on twisty roads, where you were braking hard before each bend, you would use up the fatigue life quickly as compared to blasting up the motorway all day.

Remember that the front circuit, which does almost all the braking, is guaranteed to be the one to fail first, as the pressure peaks are higher, and there is no warning at all of fatigue failure, and you will understand why it is lethal.

Coupled with this, all safety critical things should be made to conform to official specifications of one sort or another. The CDA Web site will list several official specifications to which cupro-nickel complies, and these specifications are for brake pipe. The spivs who sell copper as brake pipe may or may not quote a BS spec, but in one case the spec quoted had nothing to do with brakes or pipes, and in the more usual case the spec is about "copper tube for general use" or something similar and neither refers to vehicle brakes nor fatigue life. THERE IS NO SPECIFICATION FOR COPPER BRAKE PIPE. IT DOES NOT EXIST. IF IT IS COPPER IT IS NOT BRAKE PIPE

It is only because VOSA are utterly useless and incompetent that spivs still sell the stuff as brake pipe. It isn't and never can be. They are committing reckless endangerment and fraud. The same money-grasping, parasitic attitude that put horse meat in burgers, only with potentially far more severe consequences. No-one died from eating horse.