Replacement of steel brake lines with Kunifer.

Kendo

Zorg Addict
British Zeds
Joined
Nov 23, 2013
Points
45
Location
Scunthorpe
Model of Z
2.8 Roadster
My Z is 18 years and has advisories on its last mot for corrosion of the front steel brake pipes. I had a good look around the rear end of the car and there where brake lines in some places around the nearside wheel arch and above the diff where the integrity looked dubious. Hence my next challenge, could all of the rear fixed steel brake pipes be replaced with Kunifer having access to only a set of car ramps and axle stands? I searched the forums and found plenty of good general information on replacing brake lines generally and the tools required but nothing I could find to specific to guide me. Goods news is that it can be done. Having recently retired must admit I have the time to spend doing this hence scope eventually turned out to be:
  • Overhaul all front and rear callipers, new seals and including painting of the calipers + new EBC pads.
  • Renew all flexible hoses front and rear (6off).
  • Replace all corroded steel pipework with Kunifer.
Each brake line to rear could not be removed in one piece, I worked out two cut points where needed. With patience they where removed to enable them to be used as templates for making new lines.

pipes.jpg

View under car with new Kunifer lines installed, routing around the suspension chassis mount was awkward but having the old lines as templates saved the day.

under car.jpg

The fuel carbon filter was unbolted and moved to the side to enable better access to old pipe removal and new pipe installation. Took a small while to fiddle the old line out

rear 2.jpg

Used all of a 25ft roll of new kunifer brake pipe, most parts bought from ebay. Only part I had to buy from main dealer was the hard to flexible retaining clips as shown below, cost 85p each.

spring.jpg

Completed replacement of brake lines for about £100.
 
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t-tony

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Torksey Lock,Lincoln, England
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E89 Z4 23i Auto
Nice write up Kendo mine are starting to show some corrosion that could be sanded off but would rather replace.
Sanding down and even wire brushing is a bad idea because eventually this reduces the overall thickness of the pipe and leads to a bigger chance of it bursting under pressure. This is why the M.O.T. corrosion tool is made from alloy so that it leaves alloy in the "pitting" of corrosion when the pipe is scraped with the tool and does not remove any thickness from the steel brake pipe. Hope that makes sense.

Tony.
 

BMBabe

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Good write up!! Also I have to say your profile pic is brilliant made me chuckle :p
 
Last edited:

Jonno Bee

Zorg Legend
British Zeds
The West Country
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May 23, 2014
Points
74
Location
Exeter
Model of Z
Z3 2.8
Thanks Kendo. Good gen. I had planned this winter to sort the rear shocks, springs and suspension bushes but while I'm there I ought to renew the brake pipework.

Cheers,

Jonno
 

Dickymint

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British Zeds
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Mar 2, 2015
Points
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Location
Somerset
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Z3 2.2i Sport
Just to add I replaced my fuel lines with Kunifer and used the brake tools to flare the ends ect. so maybe worth ordering some 8mm at the same time if your fuel lines look a bit corroded (mine was at the rear where they bend up)
 

Jonno Bee

Zorg Legend
British Zeds
The West Country
Joined
May 23, 2014
Points
74
Location
Exeter
Model of Z
Z3 2.8
Just to add I replaced my fuel lines with Kunifer and used the brake tools to flare the ends ect. so maybe worth ordering some 8mm at the same time if your fuel lines look a bit corroded (mine was at the rear where they bend up)
Thanks Dickymint, more good gen and my winter to do list gets a bit longer.

Jonno
 

Steve Medlock

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British Zeds
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May 11, 2016
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Tenterden, Kent
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2.8 Roadster
Many thanks for this write up. It is likely to be invaluable when i have to do mine sometime soon. Is the copper pipe any good for this? Also are the union nuts standard metric ones?

Steve.
 

Kendo

Zorg Addict
British Zeds
Joined
Nov 23, 2013
Points
45
Location
Scunthorpe
Model of Z
2.8 Roadster
Many thanks for this write up. It is likely to be invaluable when i have to do mine sometime soon. Is the copper pipe any good for this? Also are the union nuts standard metric ones?

Steve.
Steve I used Cupro Nickel (Kunifer), its harder to work with than copper and I would recommend proper tube bender. There is lots of info on the net re pros and cons of copper vs Cupro Nickel. The latter seems generally to be the better choice. Unions and nuts standard M10 x 1 threads, bought mine from ATP-- excellent quality.
details of what I used below.......

Tubing:
http://www.ebay.co.uk/itm/191411360861?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Unions and nuts:
http://www.ebay.co.uk/itm/371609784319?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Tube Bender:
Sealey-Hand-Held-Vehicle-Car-Brake-Braking-Pipe-Bending-Pliers-VS0341
 

Dickymint

Zorg Legend
British Zeds
Joined
Mar 2, 2015
Points
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Location
Somerset
Model of Z
Z3 2.2i Sport
I was a engineer for many years and there is nothing that would make me use copper brake pipes though many people do use them with no problems and a mechanic told me they probably would never fail but probably is to high a risk for my brakes ;) and its almost the same price as Kunifer though it is a little harder its still easy to work with :)
 

t-tony

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British Zeds
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Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
Using copper tube for brake pipes is absolutely fine for the first fitting. However if you ever need to remove a pipe, to change a hose or a calliper, for example the steel nuts usually end up twisting the copper pipe as you undo the union so you will need to replace the pipe all over again. You don't get this problem too much with Kunifer pipe but it can happen.

Tony.
 

Steve Medlock

Zorg Guru (II)
British Zeds
Joined
May 11, 2016
Points
105
Location
Tenterden, Kent
Model of Z
2.8 Roadster
Steve I used Cupro Nickel (Kunifer), its harder to work with than copper and I would recommend proper tube bender. There is lots of info on the net re pros and cons of copper vs Cupro Nickel. The latter seems generally to be the better choice. Unions and nuts standard M10 x 1 threads, bought mine from ATP-- excellent quality.
details of what I used below.......

Tubing:
http://www.ebay.co.uk/itm/191411360861?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Unions and nuts:
http://www.ebay.co.uk/itm/371609784319?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Tube Bender:
Sealey-Hand-Held-Vehicle-Car-Brake-Braking-Pipe-Bending-Pliers-VS0341
Many thanks.
 
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