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| Hufflepuff Member Since: 25 Oct 2014 Location: Hampshire Posts: 723   
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Good day all. I wonder if I might feed off the combined wisdom of the Defender2.net team a little please, regarding the manufacture of brake pipes for a Land Rover.
I need to make a complete set for my 110, and thought I had collected all the tools and consumables needed to do the job. The next part was 'skilling up', which has involved a number of YouTube videos watched as well as web sites perused. As is usually the case, the more I have learnt, the more questions I have unanswered. Here is what I have found so far, please correct anything I have got wrong. Materials: Multiple types of material are available to use for the brake pipes: (1) Steel, either galvanized or coated (2) Stainless Steel (3) Copper (4) Copper-Nickel (also known as Kunifer/Conifer) The steel pipes offer good strength, but corrode even when galvanized. The stainless steel option seems to be well regarded in the USA, but less common here. Its more expensive and difficult to bend and flare, but offers great strength and corrosion resistance. Copper is easy to work with with a high corrosion resistance - but is prone to cracking. Copper-Nickel is a good compromise, being easy to work with, and more crack-resistant than straight copper. With that in mind, I went with Copper-Nickel in a 3/16" size - a common size for making brake pipes from here in the UK.  Click image to enlarge There is also a range of materials to use for the fittings: (1) Steel (2) Stainless steel (3) Brass As with the brake pipes, steel is considered poor for its corrosion resistance. However the choice between stainless and brass appears to be a less clear choice. Stainless steel fittings are a lot more expensive, for example at http://www.automec.co.uk at the time of writing the cost difference between brass is: M10 x 1mm Male for 3/16" pipe: Stainless Steel: £5.27 Brass: £1.39 The main objection to brass appears to be how soft it is - both being easy to round off, and strip the threads in the caliper if excessive torque is used when doing them up. Still, brass seems to be the most popular choice for the DIYer in the UK, so that is what I have gone with. Click image to enlarge The fittings for a 'modern' Land Rover 90s/110s/Defenders are all metric M10 threads (although I will say these brass ones seem remarkable slack in my calipers - easy to turn by hand). Tooling: Required tooling includes a brake flaring tool, for which I have borrowed off my Father: Click image to enlarge Click image to enlarge Nice to haves include: Deburring tool, pipe cutter, pipe bender(s): Click image to enlarge Click image to enlarge Flare types: There are a number of types of 'common' flares with pipes, but different places seem to mix the terms "mushroom" and "bubble" flares which is an area of confusion for me: (1) Single Flare (2) SAE Bubble Flare (3) SAE Double Flare - also called an inverted flare (4) DIN Flare - also called the Mushroom flare. Sometimes also called a bubble flare??? as shown here, shamelessly stolen from another site: Click image to enlarge The single flare is not considered strong enough for a brake pipe, and so that is discounted straight away. The SAE double flare would seem to be the obvious choice for a female fitting onto a rounded male part - for example the female fitting onto the male flexible pipe in the wheel well of the front wheels: Click image to enlarge So you get your female fitting: Click image to enlarge then make the double flare - which with my tool involves pressure "op1" before "op2" on the dies: Click image to enlarge Click image to enlarge I can visualise that this will then fit nicely into the female fitting and connect to the male flexible pipe fitting end. So far so good... However, I am getting myself into a muddle with the male fittings. If I look at the male fitting which fits into the caliper for example: Click image to enlarge it clearly has a concave indentation on the top surface of it - meaning the DIN style mushroom fitting is not appropriate - this needs a flat top to the fitting as seen on the right here - the left being the SAE bubble flare: Click image to enlarge If I look into my front and rear calipers, we can also clearly see that is it concave: If I look into my front and rear calipers, we can also clearly see that is it concave: Click image to enlarge Click image to enlarge If it was convex, like as seen here: Click image to enlarge then I would be happy that the we would be using the same SAE Double Flare that we would be using with the above female fitting into the flexible pipe. But with the calipers being concave inside, how to I know if it should be a SAE bubble flare, or a DIN flare? As it happens my tool will only make SAE flares, and my brass fittings are not flat on the top so I am really hoping it is not the DIN type. But then how do I make the SAE bubble flare anyway? The instructions for the flaring tool do not say just use Op1 and stop - it only says to use Op1 and then Op2, resulting in the SAE double inverted flare. Super confused.... Chris. 2005 Td5 90 XS 1989 V8 110 CSW |
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30th Jun 2022 10:39pm |
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| Co1 Member Since: 19 Aug 2018 Location: North Yorkshire Posts: 3618  
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I can’t help, but 10/10 for a great post!!
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1st Jul 2022 6:23am |
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| Shroppy Member Since: 25 Feb 2016 Location: Shropshire Posts: 854 
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I have to agree with Col, I always enjoy the detail of your posts Chris!
From what I can see, you've arrived at the most sensible option in terms pipe material and are getting good results with your flares. A couple of thoughts from me: - Stainless lines are pretty but I can't really see any benefit. They seem to be used extensively in trophy trucks and really high end builds in the US but cupro-nickel is a much better bet IMO. I wouldn't personally use copper as it fatigues too easily for my liking. I also recall reading an article which stated that it is not certified for use in some EU countries, presumably for a reason. - Brass fittings are indeed quite soft but brake unions do not need to withstand high torque, cupronickel can be compressed / deformed easily so they only need to be snugged down. I personally tend to use BZP unions with a light coating of antiseize on the threads, ensuring it gets nowhere near the flare. - The same goes for the slackness of the fitting in the thread, whilst I don't like it and one would expect that a good engagement could be easily achieved, I have had no issues with this in the past. As the union starts to engage with the pipe (which itself is pressed against the female union be that inline or at the calliper) a seal is created between the calliper-pipe-union such that the threads aren't required to seal. - For many years, I thought SAE double flares were the norm. They are indeed correct for the applications you have identified (connecting to flexis etc) but from what I can see, it looks as though you need the SAE bubble flare for the male union - calliper connection. 'OP1' on your tool should create the SAE bubble flare, 'OP2' simply forces the convex portion of the SAE bubble flare inwards to create the SAE double flare. In reality, a SAE double flare would probably seal in the male union - calliper connection and indeed I'm sure it is working in many applications, on many vehicles across the world. However, matching the flare to the profile of the union is the 'correct' method in my opinion. 1985 127 V8 Build Thread Series 2 109" Series 1 80" Last edited by Shroppy on 1st Jul 2022 11:22am. Edited 1 time in total |
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1st Jul 2022 8:39am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 16920 
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It is easy to tell whether the original male fittings are DIN or SAE, since the DIN will have a flat face and the SAE will have an internal chamfer. As far as I recall recent Defenders use DIN fittings.
As a basic rule, inspect what you have taken off and then recreate the same flare form for the new pipe. Personally for new brake lines my preference is to use Cunifer pipe and BZP steel unions. Over the years it has been very rare that I have had trouble removing an old fitting and on those occasions the parts were usually beyond salvation anyway. Although I have no reason to suppose that they are unsatisfactory personally I would not use brass fittings, nor buy a vehicle which used them unless they were originally used on the production line. Bear in mind that under sever braking you may be generating pressures of around 150bar in the brake lines, and I don't like the thought of brass fittings being asked to withstand 2000psi. It is also worth investing in a good brake union spanner or flare nut wrench of the appropriate size, it makes more difference than you would perhaps expect to the successful undoing of old unions. |
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1st Jul 2022 9:39am |
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| Hufflepuff Member Since: 25 Oct 2014 Location: Hampshire Posts: 723
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Thanks as always for the replies gentlemen. My Father has just said the same as you said blackwolf with respect to the brass fittings. Its a pity as that wasn't a cheap set but ho hum, you can't take it with you.
I'll check to see if the taken off fittings were of the DIN variety, and if so order up some BZP steel DIN fittings, and a DIN flaring die. I have replaced/changed the entire brake system on this vehicle, from the master cylinder to the calipers (now sporting vented front discs, and a rear drum to disc conversion, so it won't exactly be comparing like for like but it will give me some idea what Land Rover were using in 1989. 2005 Td5 90 XS 1989 V8 110 CSW |
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1st Jul 2022 8:16pm |
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| jfh Member Since: 08 Jan 2014 Location: West Coast Posts: 349  
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You can also watch the rest of this series. |
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1st Jul 2022 8:22pm |
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| Mossberg Member Since: 29 Feb 2020 Location: Lancs Posts: 552 
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I used brass fittings and will do so again. The reason I used brass is that the steel ones that were on originally corroded between the fitting and the pipe. They unscrewed OK, but because of the corrosion between the fitting and pipe, the pipe twisted as I undid it. If you think you should use steel fittings because the originals were steel, would you not also feel you had to use steel pipe? Whilst I can't give advice or the definitive engineering advice on brass threads, if you are worried about the threads, how do you feel about the tube being held in by the flared end of the pipe as I would think there is less "meat" on that one section of pipe than there is on the threads. You have to work with what you are comfortable with, but I would happily use the brass fittings if you are giving them away 😊. The brake pipes on my rear axle split (as in went left and right, not literally split the pipe!) at a brass T piece, 30 ish years old and still serviceable. People have noted that the brass could potentially round off easier, but hopefully less corrosion will mean the hex retains its shape, so with less likelihood of seized threads hopefully with a good sized spanner they will be OK. I bought some flare-nut spanners off ebay and they work well. They go upto 24mm and they are a good fit and strong enough. Better than using a spanner that can slip or round the fitting. I think it was about £20 for the set but I feel a good investment. Unfortunately I can't find the listing or I would post it here. |
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2nd Jul 2022 7:37am |
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