New brake pipes!

[Jonny-Jimbo]

Hi all,

I need to make new brake pipes for my 2000 mk1 - when I was removing the flexi-lines the old steel lines fractured. To be expected as they looked original to the car!

I have copper and kunifer pipe I can use that I think is the right diameter (around 0.18", which I think is 3/16"). However, assuming that the pipe is the right diameter, can anyone tell me what the flare form is that I need on the ends of the pipe? One end will go into the 4-way adapter on the inner wing by the battery box, and the other end will route under the chassis rail in order for the new flexi-line to attach to it.

Can anyone tell me the right thread forms (SAE / DIN etc?) and if they are 3/8 long or short I need on the 4-way adapter.

Thanks, Jon

[Gt6s]

3/8 UNF, male fittings have single flare female fittings double flare.

Laurence

[TedTaylor]

If flaring steel or cupro nickel don't use one of the screw thingys as they do not give a good flare.  Use on of the proper Sykes Pickavant or similar lever and cam type - the straight action produces a much better flare on the tougher pipe.

MUT

[Jonny-Jimbo]

Thanks guys, will be using copper pipe as I already have some of the right size.

Could you tell me what the flair profile is though? There seem to be loads of different types and I have no idea what is the one I need.

[RobPearce]

I've used a set like this:

for years and never had any trouble. I think I bought it from Eastwood, possibly available from Frost now.

[dazzer]

Mental note when making flares. Always remember to pop the collars onto the pipe before you make the flare...  been there done that.

[Nick Moore]

Quoted from Jonny-Jimbo

Thanks guys, will be using copper pipe as I already have some of the right size.

Could you tell me what the flair profile is though? There seem to be loads of different types and I have no idea what is the one I need.

Jonny, you're a far better mechanic than me, judging from your list of cars and where you work. Can I suggest, though, that kunifer pipe would be better than copper? It's just as easy to work, but doesn't get fatigue fractures like copper is said to do.

[nang]

I'm surprised that you are able to use copper. It's illegal on brakes in New Zealand because of its work hardening characteristics. This causes fatigue fractures as Nick says.
Tony.

[piman]

Hello Nick/Tony,

according to Automec who sell both copper and Kunifer, there is no difference in reliability or strength between them, down to personal choice. Note that the copper they sell is thick wall, and not all copper brake pipes are necessarily so. They do need more clips than the original steel.

Alec

[Jonny-Jimbo]

Quoted from Nick Moore

Jonny, you're a far better mechanic than me.

Bollox - Your DIGG GT6 is a work of art, and far better than I could do.
Just because I have a pile of old cars and bits does not mean anything... Anyway...

Thank you for the points about copper, but as Alec has said, Automec (who's brake pipe and fittings I will be using) say there is no difference between the two. However, as I have suitable kunifer pipe too I may use that. I think the flaring tool I have bought is up to the job on copper, kunifer and aluminium.

Thankyou for the pointers all.

Now I just have to hope that the flare form is correct. (SAE, DIN etc...)

[TedTaylor]

I personally never use anything other than bundy (for cars of special interest and want originality) or cupro-nickel (for anythng else) because it is a much tougher material than copper.  

From my Land Rovering days I have seen situations where a stone has struck a copper pipe and flattened it, and also as Alec has pointed out you must use more clips to support the pipe to reduce any risk of vibration and work hardening.

There is a difference between the properties of cupro-nickel and pure copper because of their chemical make up, and really the only benefit that I can see in copper is that it can be easier to form (which says something about its ultimate toughness) so easier for the home mechanic.  

There is also another problem that I have found with copper pipes.  When I have had to remove them (because fitted by someone else) the copper jams in the union because of its softness and so when the union is undone undone the copper pipe screws up and gets destroyed.  Light greasing on assembly helps to prevent this a little but only if the person who fitted the pipes does it.  Automec probably don't worry about this problem because they will simply sell another set of pipes .........

MUT

[josh18]

What kind of benders are you guys using to form your lines out of interest?

[TedTaylor]

Quoted from josh18

What kind of benders are you guys using to form your lines out of interest?

I have a small collection accumulated over the years, when I get a moment I'll post a photo of them.  A number came from places like B&Q and there are a variety of others designed for forming brake pipes.  Many are cheap enough in my opinion to be able to have a collection for different radius curves and pipe (larger for petrol if you ever need it).

A word of caution if using the pliers type:
Do not twist the tool to form the bend as it is likely you will cause the tool to put a kink/nick/groove in the pipe which a zealous tested could use as a reason for failure ..... and he is probably correct!
Hold the pipe firmly in the tool with one hand and with the other hand push the pipe to make the bend against the curved groove in the pipe.  
Even then it may nick to pipe so just be patient, take care, and practice on an offcut if you have any.

I prefer to bend the pipe to shape and then fit the unions on the ends when I know it is all shaped and will fit on the car nicely (though this can be a problem if there is a bend very close to the union).  You obviously cannot do this if you are using pipes from kits where the unions are pre fitted.

MUT

[ferny]

http://www.screwfix.com/p/irwin-hilmor-multi-mini-tube-bender/28586

But I just use my thumbs normally.

[Tim Bancroft]

I have had a Automec brake pipe kit on my GT6 since 1993, no problem at all. Top quality products.

[Richard B]

http://www.sykes-pickavant.com/downloads/braking%20-%20draft%20-%2019-12.pdf

My kit is the  "‘270’ Series Brake Pipe Flaring Tool"

SAE is the imperial flares, DIN is the metric flares. Well thats what it says...



In fact reading further SAE & DIN are the same for double flares, the difference is the profile of the single flares.

[nang]

I've got one of these. Brilliant tool.
Tony.
http://www.ebay.co.uk/itm/Brak.....6:g:emwAAOSwll1Wwa6O

[piman]

Hello Ted,

the problems you encountered with twisting of the pipe when trying to slacken it, were the fittings brass or steel? My experience with brass has been good.

Alec

[RobPearce]

Quoted from piman

Hello Ted,

the problems you encountered with twisting of the pipe when trying to slacken it, were the fittings brass or steel? My experience with brass has been good.

Likewise. In fact, I think the pipes that twisted as I was undoing them on Tessa the other day were actually cunifer - but with steel fittings.

[TedTaylor]

Quoted from piman

Hello Ted,

the problems you encountered with twisting of the pipe when trying to slacken it, were the fittings brass or steel? My experience with brass has been good.

Alec

Nope Alec they were brass and steel on different occasions which is why I steer clear of copper pipes.  

I think the problem is that people tighten copper up so much to get a good seal that it deforms into all the recesses of the union and its seating so that it jams.  With bundy and cupro-nickel the deformation to form the seal is more controlled due to the greater toughness of the tubing.

MUT

[TedTaylor]

Quoted from RobPearce

Likewise. In fact, I think the pipes that twisted as I was undoing them on Tessa the other day were actually cunifer - but with steel fittings.

Rob I have never experience any problem with curonickel and been using it for 30 years - invested a 270 series Sykes flaring kit to be able to do it.  Can't believe it is down to my fitting technique.

Also copper does look tike cupronickel and often the only way of being sure is the file or hammer test.  Also copper is very easy to bend but cupronickel is harder.

MUT