I'm in the process of renewing all the brake pipes on the car, from front to back.

I was under the impression that the flares were the SAE type, but having looked that the OEM pipe i'm slightly confused.

Can anyone shed light on this?

many thanks,
Adam

They'll be DIN.

Recently, when changing the axle, I found a definitive answer to this.
SAE flares are tapered on both sides of the flare. So the nut has an internal taper as well as the fitting the pipe goes to.
DIN are flat on the back of the flare, so the nut is also flat faced.

If using copper pipe, it probably does not matter as it is soft enough to seal whatever, and unless you spend hundreds on a flare tool the flare will be imprecise anyway.

portland_bill said:

They'll be DIN.

Recently, when changing the axle, I found a definitive answer to this.
SAE flares are tapered on both sides of the flare. So the nut has an internal taper as well as the fitting the pipe goes to.
DIN are flat on the back of the flare, so the nut is also flat faced.

If using copper pipe, it probably does not matter as it is soft enough to seal whatever, and unless you spend hundreds on a flare tool the flare will be imprecise anyway.

Click to expand...

Thank you! So I’ve purchased the wrong flare kit, I need a DIN version.

I had a shop make up some pipes in copper but I wasn’t happy with them and the fact some were too short and some too long.

I bought a roll of kunifer and started making my own but then I realised the ends just didn’t look like the OEM pipes. To be fair, the copper ones that were made are also wrong they appear to be SAE.

So my final question is, on the copper pipes that were made, they supplied some new fittings, will I be able to use these? Or do SAE vs DIN use different fittings?

I’ve struggled to remove the original fiat ends due to really bad corrosion, the car is 15 years old.

I plan to hold onto to the car now for many years to come and just use it in summer. I’ve already had the car 10 years and it’s a labour of love.
Maybe it might be a classic in many years time. I’ve now renewed the rear axle with good second hand version I already had in the garage, the last job are these pesky brake pipes!

HEL braided hoses will work with either type of flare.


My plan was to fit braided hose for the back end from ABS to wheel with a joint at the axle/chassis area. The ABS end was probably going to get a banjo fitting but I never got to that level of detail befpre dropping the idea.

I was stopped by the bad access at the ABS block and (to be honest) my metal hoses were actually not bad when looked at more closely.

Costs are not "that" bad. Up to 1m of hose with fittings is £20 plus £5 per metre of longer hose so 2m would be £25.

AAB1992 said:

Thank you! So I’ve purchased the wrong flare kit, I need a DIN version.

I bought a roll of kunifer and started making my own but then I realised the ends just didn’t look like the OEM pipes. To be fair, the copper ones that were made are also wrong they appear to be SAE.

Click to expand...

Very difficult to get kits to make DIN flares. Unless you wish to spend mega money.
I found one of these: https://www.ebay.co.uk/itm/A-P6FT-B...m-Hand-Held-/123212124582?hash=item1cb003d1a6
Quite happy with it. Acceptable DIN flares for the price. Have to spend 3 times that amount for a professional tool if you want better.

AAB1992 said:

So my final question is, on the copper pipes that were made, they supplied some new fittings, will I be able to use these? Or do SAE vs DIN use different fittings?

Click to expand...

The fittings need to match the flares.
This helps:https://www.ebay.co.uk/itm/Vw-Class...ng-Tool-Kit-/272815004353?hash=item3f850a9ac1
Look at the second pic, and the flare differences are clear. The dome that fits into the wheel cylinder or hose is close enough to be no worries. It is the back of the flare in the fitting that is important.
An SAE fitting should have a taper inside to match the back of the SAE flare.
A DIN fitting should be square ended to push against the flat back of the flare.
First check the new fittings. Do the threads fit the car. There are SAE metric and UNF threads. But all DIN should be metric. I think SAE metric and DIN metric have different head sizes, although the thread is the same. If the head is larger, check clearance for your spanner before committing.
If your new fittings are SAE, make SAE flares and fit them.
If your fittings are DIN, make DIN flares.
If you can't make DIN flares, buy some SAE fittings to go with your tool.

https://www.ebay.co.uk/itm/Land-Rov...h=item2f059ccf5b:g:dQkAAOSwurZZMSxH:rk:4:pf:0

I was thinking upgrading to these, they are correct size and pitch, although it doesn't say if they are for SAE or DIN.

I was under the impression that DIN fittings aren't threaded all the way like in the link. Although they don't have a flat face?

The fittings that I have from the local shop look correct, but because they are cheap in not sure if these are prone to corrosion? The original fiat ones don't corrode, not sure what material they are made from.

https://www.automec.co.uk/products/brass-brake-pipe-fitting-male-m10-x-1mm-short-din-3-16

These say for DIN but they don't have a flat face?

This looks like a reasonable guide
http://racetrackdriving.com/tech/brake-line-flares-metric-sae-inverted-bubble/

As an aside note that the "AN" fittings that are used with "Aeroquip" hoses and single flare rigid pipe have a 37 degree flare.

AAB1992 said:

https://www.ebay.co.uk/itm/Land-Rov...h=item2f059ccf5b:g:dQkAAOSwurZZMSxH:rk:4:pf:0

I was thinking upgrading to these, they are correct size and pitch, although it doesn't say if they are for SAE or DIN.

I was under the impression that DIN fittings aren't threaded all the way like in the link. Although they don't have a flat face?

The fittings that I have from the local shop look correct, but because they are cheap in not sure if these are prone to corrosion? The original fiat ones don't corrode, not sure what material they are made from.

Click to expand...

If the picture is what you get, they are SAE. You can see the internal taper.

AAB1992 said:

https://www.automec.co.uk/products/brass-brake-pipe-fitting-male-m10-x-1mm-short-din-3-16

These say for DIN but they don't have a flat face?

Click to expand...

From my experience of Automec, market leaders, you will get whatever it says. They do however use generic pictures, so for them, believe the description. For others, trust nothing.

If you are replacing end to end does it matter if they are DIN or SAE fittings?

HEL hoses (and no doubt other brands) work with DIN or SAE.

Copper pipes work harden so cunifer really should be used. By the time you have bought the correct tube, properly plated fittings and professional tools, you might as well use braided hoses in place of the metal tubes. They are flexible so easier to get into place than stiff metal and you can use banjo fittings which are often easier to get into place. Fittings are stainless and the hose wont expand under pressure so you wont have a springy brake pedal. You could use rubber hoses to the wheels or braided.

I used HEL because they are local to me but was impressed with their factory operation.

So I’m confused once again.

SAE have single and double flares.
DIN have single ends.

I cannot find any information on the DIN female flare end because the replacement flare tool only does DIN single!

Do you just join up both DIN single ends with a male and female end?

I’m getting quite fed up of working on brake pipes! Grrr

May have to go with something like this if no solution is found: https://www.ebay.co.uk/itm/Metric-B...=item2eea9856fe:g:NwQAAOSwuYVWn~2K:rk:31:pf:0

However, i'm still not sure if this is SAE or DIN :bang:

AAB1992 said:

So I’m confused once again.

SAE have single and double flares.
DIN have single ends.

I cannot find any information on the DIN female flare end because the replacement flare tool only does DIN single!

Do you just join up both DIN single ends with a male and female end?

I’m getting quite fed up of working on brake pipes! Grrr

Click to expand...

Reading this thread has got me thoroughly confused too! It got me to thinking, OK, forget about all of this. You've (that is me) been doing brake pipes for at least 40 years so how do I handle it? Oh dear - mega post coming up! I think I did a bit on brake pipes a while ago but can't find it.

Thinking about all this DIN and SAE "stuff" I work on classic and later model vehicles so the first thing I want to know is what thread is the union nut. I keep spares and simply try one in the mating component. The shapes are quite distinctive too which helps. In the following image the ones on the left are imperial and on the right metric. The two at the back are metric but in brass (at one time I fitted these in the attempt to stop corrosion but I've gone back to standard fittings these days). The union at the front, which looks like the one you found on line, I use if I need to join on to an existing pipe on the car (for instance where you have to cut out part of a front to rear pipe and join in a new bit).



Then comes this thing about the form of the flare. People get very het up about the "metric" flare having a very flat back face (where the nut pushes against it and a less domed front end (on the No1 - convex - flare) in comparison the imperial flare has a conical back end and more domed front face. However, in practice, using cheaper DIY type tools, have a look at this and see if you can see the difference.





The pipe has been flared with an "imperial" No2 flare so it's back face is conical. The first picture shows it on a tube nut with a Metric type flat face. The second a nut which is internally chamfered. See the difference? it's very slight isn't it. I deliberately chose the "imperial" flare because by far the majority of cheap DIY flaring tools I've seen do this type of flare.

You would think the conical nature of the back of the flare would stop it sitting properly into the DIN nut, So why isn't the first one standing more proud of the nut? Well, take a look at these,



The two on the left are flat faced (an imperial thread on the very left) and the two on the right are chamfered. Not much of a chamfer really is it? But the really interesting bit is look carefully at the flat faced nuts, magnify the image a bit, the clamping face isn't exactly flat is it? it's rounded off a bit. I've looked back through my box of spare ends and they're all like this. The big worry is that if you have a nut with a very squared off mating face and a pipe with the "imperial" (would that be SAE?) type then as you tighten it it's going to cut through the conical back face of the flare. I have two flaring tools so here is a test piece of pipe with a flare from one on one end and the other on, well, the other.





I've made flares with both these tools on many pipes and used them with both imperial and metric nuts - never had a problem. I think that although there may be small differences in form, the pipe material (I use Copper and/or Kunifer pipe) is sufficiently compliant to deform to shape - after all even with a perfect flare the material is still going to deform as you tighten it, that's how it seals!

I'll wrap this up here but I'm now going away to do something more general about my flaring tools etc - I'll be back soon (Oh No! I hear them all groan!)
keep safe everyone (particularly apt wish to anyone working on brakes)

Corroded brake pipes. failed MOT. B****r! A load of hassle isn't it? So, unless it's a one off, just make your own. There's a big choice of tools to fit all pockets. Can I say this is not intended as a guide to making your own pipes but rather an entertainment for you on my gear. If you have a go at it you must take great care - faulty brakes are lethal!

A good place to start is with deciding on what pipe to use. Most DIY grade flaring tools will not satisfactorily flare steel! This actually isn't too much of a problem because high quality copper pipe is readily available and is used in many commercial establishments. Copper though has two weaknesses. It is soft (that's good because it makes it easy to work) but it is prone to sagging on long runs so may need extra brackets to support it. Also it work hardens. This second property means it's banned in many countries - but not here - an immediate problem this causes is that you must only bend it once, don't try to straighten it if you get your bend wrong (unless you anneal it) but, more insidiously, people worry it may crack or fracture due to vibration and flexing on the vehicle. I used to worry about this but don't now because I have never seen this problem and have never talked to another mechanic who has. (bear in mind the pipes must be supported properly as when the original was fitted. The problem with sagging on long runs I overcome by using Kunifer (Cupro Nickel) pipe. It resists corrosion very well but is stiffer than pure copper so behaves much more like steel. The Kunifer also has a much higher recommended max pressure compared to the copper 214 bar compared to 127 bar. but 127 bar is still far in excess of anything you can create in a normal braking system. Here's some images of pipe, and a packet of tube nuts, as you buy them from the factor:









All the local garages seem to use copper now a days and it causes some hilarity when I ask for the Kunifer.

Once you've carefully measure the length of pipe needed (do this carefully to get a neat result) it's got to be cut from the roll. a mini pipe cutter like this makes life easy.



It cuts the pipe nice and square and slightly bevels the outer edges. You should carefully clean out the burrs from the inside of the cut too if you want your forming tool to last. If you cut the pipe with a mini hacksaw you must square off and deburr carefully. I also slaister silicon grease on the end of the die too.

So now to my tools. Shortly after leaving college, back in the late '60's I bought this:



Here it is with the die head split. You can see the shape of the die which forms the back of the flare. When the other half of the die is assembled it grips the pipe firmly. A forcing bolt, which has the shaping die inserted though it, screws into the other side. The forcing bolt is tightened firmly and the flare is formed.



Here it is with the shaping die in place



Here are the two dies which form the end shape. No1 (convex, some say "single" flare) on the left, No2 (concave, come say "double" flare) in the middle. The piece on the right is a stop piece to set the correct pipe depth for flaring.



Many years later I bought this tool as I understood that it produced a more "square backed" flare - more like the metric shape.



It works well enough but isn't any better than my original tool. There is one thing I don't particularly like about it though. My old tool keeps it's die straight by having a long tang on the forming die (which goes through the forcing screw) This tool does it by having a long, and much less substantial, tang on the end of the forming die which actually enters the bore of the pipe.



This tang, you can see it here compared to the old tool's die, tends to get crushed and held by the pipe as the flare is formed. sometimes, especially with kunifer which takes more force to form, I worry it's going to break as I try to withdraw the die from the end of the tube. Also the instructions which come with the tool say to set the pipe level with the face of the tool to allow for the correct "crush" I find that to form a robust flare you need to double this height. When you do this you can only just get the forcing screw to swing round over the die.





So there you are. My tools and experiences, for what they're worth. I do prefer my "old friend" from all those years ago. we've spent many "happy" hours together under a wide variety of motors, with me inventing new and obscene ways to swear at stubborn brake pipes! He's very "honest" too, as he only ever claimed to be able to "do" one size of pipe. The "young pretender" makes promises he can't possibly keep:



I don't think so chum! Oh, just a parting thought, Don't forget to put your tube nuts on - right way round - before you flare the other end of the tube will you!

Thanks Jock. to do the bob properly (and these are brakes so nothing else will do) we need proper tools. It was that and the issues over copper or cunifer (btw does the end have to be annealed?) that made me consider end-to-end braided hose. It's MOT compliant and frankly so much easier. It hardly any more money though the additional costs would add up in a car factory so they continue to use metal pipes.

My 100HP back axle has a 600mm HEL hose from caliper banjo to the floor pan bracket which replaces the previous two rubber hoses and short metal pipe. The chassis end has a swivel so there are no worries about twisting the hose. That cost £20 per side. Another hose from there to the ABS block would add £30 per side.

DaveMcT said:

Thanks Jock. to do the bob properly (and these are brakes so nothing else will do) we need proper tools. It was that and the issues over copper or cunifer (btw does the end have to be annealed?) that made me consider end-to-end braided hose. It's MOT compliant and frankly so much easier. It hardly any more money though the additional costs would add up in a car factory so they continue to use metal pipes.

My 100HP back axle has a 600mm HEL hose from caliper banjo to the floor pan bracket which replaces the previous two rubber hoses and short metal pipe. The chassis end has a swivel so there are no worries about twisting the hose. That cost £20 per side. Another hose from there to the ABS block would add £30 per side.

Click to expand...

Thanks Dave, I followed your other posts on this subject with great interest. At first, probably because I'm used to thinking about getting the job done with metal pipes and the usual flex hoses, I didn't like the idea. But now, after quite a bit of thinking about it, I'm warming to it. Are they projected to outlast conventional replacement pipes?

Copper or Kunifer? As I don't worry to much about the copper hardening thing any more I don't tend to get too "up tight" about it but I tend to use Kunifer by preference, and always on long runs, but copper comes into it's own on short runs where lots of bends are required. For instance from a wheel cylinder around a hub and along a suspension arm perhaps with a nice little right angled turn to the flex hose on the front of the axle?
As regards the need to anneal before forming. The metal is unworked at that stage so it forms easily. I find the preparation of the end of the pipe makes a big difference to the quality of the flare - nice and square, outer edges slightly rounded and the bore deburred. Also use a lubricant on the forming faces of the die (brake system friendly so silicon or "red" grease etc) it lets the metal "squirm" without picking up on the die as it's being formed and I find gives a smoother finished job. Of course it saves wear on the die too. I finish off by blowing the tube out with compressed air. If the flare isn't good cut it off and start again, don't try to "remake" it. A poor flare is often due to 1) not enough pipe protrusion before clamping up. 2) not fully tightening the forcing screw (but avoid over tightening or the flare will be over compressed and tool damage can occur - there's definitely a knack to this and you need to do a few practices if you've not done it before). 3) not fully tightening the die body which clamps the pipe. In this case the pipe will be pushed through the die body as the forcing screw is tightened and an incomplete flare will result. (this one can catch you out as it's not obvious what's happening if you are not aware of the possibility and is common on old worn tools)

Btw, one of my best friends is called Bob, his wife assures me he has been"done proper"!

Regards
Jock

g8rpi said:

This looks like a reasonable guide
http://racetrackdriving.com/tech/brake-line-flares-metric-sae-inverted-bubble/

As an aside note that the "AN" fittings that are used with "Aeroquip" hoses and single flare rigid pipe have a 37 degree flare.

Click to expand...

interesting article - I enjoyed reading it. Seems to come to the same conclusion as me that even if your flares aren't angle perfect, but near enough, the "softness" of the pipe material allows distortion to effect a seal.

Just thought I'd throw in that, with my experience of using flaring tools both at home and commercially, I consider that being able to form flares on the vehicle in tight situations to be very important and, as most OE pipes are steel the tool needs to be robust. There are two designs in particular that interest me, The Laser 6728 and, if you look on the FROST website there are a couple - product code M 101 and M 102 (SEA and DIN) They both seem to claim to be able to do steel pipes and are of the same generic design as my "old pal" Until recently I would have given a lot to own a Sykes Pickavant Flaremaster 2, and I still hanker after one, but it is considerably more bulky than the two mentioned above so would not be so "usable" in tight corners. For the same reason I'm not so keen on the "scissors" type which mount the forcing screw on a bridging piece (many of the really cheap examples are of this design). There is a video on the Laser site which illustrates very well the usability of the 6728 in tight corners. Last week, when I popped into the local Honda independent, they were flaring a front to rear pipe to accept a "patch in" as the union at the back end of the pipe proved too corroded to screw back into the new flex hose that was being fitted. The tool they were using looked very like the 101/102 shown on Frost's site - it was doing a lovely job.
regards Jock

I was going on about braided stainless hoses from end to end. Nothing is 100% perfect - these struggle with really tight turns and MUST NOT be twisted so have to be carefully clipped working from one end.

There is also more than one option. Factory made (crimped) braided lines need careful measurement as there are no second chances if yours is too short/long, but you do have the OEM metal line as a pattern. Venhill is another option as they have compression type end fittings so you can make your own. I liked HEL factory made because of their swivel ends and range of fittings.

From a maintenance point of view - there is none, but any damage will require a complete new line. You cannot cut away the damaged end and connect a new length, as you can with a flaring tool. They don't corrode and fatigue damage has not been reported - they are flexible after all.

So if you don't have the flare tools and are replacing a whole line from Master cylinder/ABS to chassis bracket, A braided hose will be great. If you are repairing a corroded pipe end and have the tools, a copper tube is less cost and less hassle.

Thanks for all the comments! It’s GREATLY appreciated. I know I’ve been quiet of late, I’ve been trying to finish the entire job off despite the cold weather. So initially the job consisted of changing the rear axle bushes but the old axle was beyond saving after the harsh winters we’ve had in the north over the last 9 years. I had a spare from a few years ago that was in good condition that I just had to refurbish. So in the end the job has cost around 300 pounds for the tools and materials.

So the parts list..... new nuts and bolts, new flexi hoses, new axle brackets, new shocks, refurbished stub axles, all the drum brakes have been cleaned, adjusters renewed and transferred to the newer axle, new handbrake cables, all new pipe work from back to front (ABS unit). It’s taken weeks.

On the subject of pipes... the old ones couldn’t be saved, they just wouldn’t undo without twisting. 15 years had taken its toll. I tried to flare the old pipes, but with the new male ends, due to the plastic coating they didn’t fit! I had some copper ones made up, but they weren’t cut to the right size or had the “right type” of flares. So in the end I made my own out of of kunifer with a mixture of male ends and joins using female/female unions. I I’m please to report that this method did work. The original pipework was installed when the fuel tank wasn’t in thus making life much easier. In the end I had to make a pipes from the ABS unit (very tricky I may add!) to the front section of floor. Then sort straight sections to the rear floor. From there I managed to make a pipe that went along side the fuel tank (tricky also! Using the existing routing). Then from the flexi’s to the wheel cylinders. All the flares I used were DIN, so they’d match with the profile on the ABS unit and flexi’s.

So 3 weeks later I’ve got brakes that are working and not leaking! Plus an axle that isn’t rotten. I don’t intent to take the car out in winter anymore so hopefully corrosion shouldn’t be too much of a concern.

I followed Daves advice with the rubber pads top and bottom and all seems well. Fingers crossed the car will last another 10-20 years now, when it will be consigned to the classic car world! [emoji23]

I hope to see you all at the events over the coming year.

Thanks once again
Adam