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Hi, today I filled the new brake line with fluid and found all the connection points leaking.
What could be the reason, considering that it leaks from any connection?
Overtightening? mishaping of the flaring? What else?
Posibly bad flares (or wrong flares) but doubt you'd have that on every end (unless you really fecked up when making them).
Undertighteningis more likely. On first fitting, remember there'll be a fair amount of compression of the new flare after the initial contact and
before it's tight.
Never seen a leak caused by overtightening.
I will post some photos later
Have you even remembered to tighten them up? sounds stupid but I've done that before. It's amazing how many times I've forgot to
tighten bolts up, especially when in a rush or working at night. A paint pen is a really good practice for marking off anything fully tightened.
Might be that you've done the wrong type of flare, some need a double to make up the clearance. Another possibility is mixing up metric with
imperial. There's one type of fitting that actually screws together but doesn't grip right. If they are all leaking then there's
something fundamentally wrong with your method you need to investigate.
It'll be interesting to know what you find. For me I have a concern around the initial tightening. As Adithorp mentioned I am expecting the first
tightening to need a little more 'oomph' to get things to sit right. But I'm using Kunifer rather than copper, which I've already
realised is a fair bit stronger to form and bend. So I'm expecting to have to tighten things even tighter than normal.
What does sound unusual for you is that it's 'every' join. On the assumption that you have a variety of joins (pipe to flexi, pipe to
t-joint, pipe to brake cylinder etc), it does suggest a process issue. Is it definitely every join or are there at least some that aren't
leaking?
Have you flared brake pipes before, are you comfortable with how they were done?
Process used to flare:
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quote:
Originally posted by Slimy38
It'll be interesting to know what you find. For me I have a concern around the initial tightening. As Adithorp mentioned I am expecting the first tightening to need a little more 'oomph' to get things to sit right. But I'm using Kunifer rather than copper, which I've already realised is a fair bit stronger to form and bend. So I'm expecting to have to tighten things even tighter than normal.
What does sound unusual for you is that it's 'every' join. On the assumption that you have a variety of joins (pipe to flexi, pipe to t-joint, pipe to brake cylinder etc), it does suggest a process issue. Is it definitely every join or are there at least some that aren't leaking?
Have you flared brake pipes before, are you comfortable with how they were done?
Your flare looks properly formed but it does look quite small, looks as if the nut might contact the bottom of the port without compressing the flare.
Possibly a trick of the camera.
Other thoughts:-
Are your flare nuts long enough, ie there still some thread showing when the nut is tight?
Are you using the correct flare to match the port ie convex or concave?
Cheers
Davie
Couple of things from those pic's (looking on my phone and a bit blurry zoomed in)...
The flare in pic 3 looks a bit small and in pic one the pipe might need to be further out before flaring to correct. Pic 2 looks like a double/concave
flare and three a single/convex ? Pic 3 also seems to have some damage to the pipe behind the flare.
quote:
Originally posted by daviep
Your flare looks properly formed but it does look quite small, looks as if the nut might contact the bottom of the port without compressing the flare. Possibly a trick of the camera.
Other thoughts:-
Are your flare nuts long enough, ie there still some thread showing when the nut is tight?
Are you using the correct flare to match the port ie convex or concave?
Cheers
Davie
quote:
Originally posted by MadMaxx
Good tips e following my observations:
- I will check if the flare is really compressed (that's my major concern)
- The leaking is between the pipe and the nut compressing it
- Yes, some thread is still in sight after having tightened the nut
- Could the dents left by flaring tool influence the bedding of the flared end of pipe between the nut and the case?
The counter-sinking on the nuts looks a bit excessive?
Just checks all my spares and they don't have any counter-sinking!
I have these CBS nuts
quote:
Originally posted by adithorp
Couple of things from those pic's (looking on my phone and a bit blurry zoomed in)...
The flare in pic 3 looks a bit small and in pic one the pipe might need to be further out before flaring to correct. Pic 2 looks like a double/concave flare and three a single/convex ? Pic 3 also seems to have some damage to the pipe behind the flare.
[/img] quote:
Originally posted by daviep
quote:
Originally posted by MadMaxx
Good tips e following my observations:
- I will check if the flare is really compressed (that's my major concern)
- The leaking is between the pipe and the nut compressing it
- Yes, some thread is still in sight after having tightened the nut
- Could the dents left by flaring tool influence the bedding of the flared end of pipe between the nut and the case?
Where are the dents? if they are from the clamping bar then I would not expect them to cause sealing problems.
If you remove a union that you have tightened you may be able to see a witness mark either on the bottom of the nut or in the port, if the the nut has contacted the bottom of the port.
You can also make a test piece and assemble it on the bench to allow you to test whether the pipe is properly clamped.
Davie
If the flare isn't sealing then the leak will be between nut and pipe. It won't appear up the threads as they're tight so it'll go
route of least resistance up the pipe.
As said above that countersink in the nut looks wrong for a metric nut. More like an old UNF.
Also if the flare in your picture is after fitting, then it's definitely not been compressed fully as I'd expect (is there an odd ridge in
the back of the flare as well?).
[Edited on 31/5/22 by adithorp]
The countersunk male tube nuts are for sae type single and double flares, the flat ended male tube nuts are for din flares, and female tube nuts are
for sae double flares.
Most european cars use din flares, ford do use din male to sae female on ka/fiesta/focus rear brake pipes (to save the cost of a female-female
connector), but should otherwise be seen as incompatible with sae fittings, things are even less clear where metric threads are being used with sae
flares which is quite common on japanese and us market vehicles.
Most din applications use nuts with an unthreaded section at the flare end, if you use fully threaded nuts in place of these, the thread will bottom
out before a seal is made as they are not fully threaded at the female end.
I did have a good chart with all the options, but cannot find it at the moment, it also had sectional views to help identify the correct fitting where
the original was not available
Dave
dito the countersink issue, first I've seen those tbh. I only use the type without that, you may have found the problem. Sadly its new pipe time
I think your over tightening the clamp as you've left some quite deep marks in the pipe.
[Edited on 31/5/22 by Mr Whippy]
quote:
Originally posted by adithorp
If the flare isn't sealing then the leak will be between nut and pipe. It won't appear up the threads as they're tight so it'll go route of least resistance up the pipe.
As said above that countersink in the nut looks wrong for a metric nut. More like an old UNF.
Also if the flare in your picture is after fitting, then it's definitely not been compressed fully as I'd expect (is there an odd ridge in the back of the flare as well?).
[Edited on 31/5/22 by adithorp]
quote:
Originally posted by Mr Whippy
dito the countersink issue, first I've seen those tbh. I only use the type without that, you may have found the problem. Sadly its new pipe time
I think your over tightening the clamp as you've left some quite deep marks in the pipe.
[Edited on 31/5/22 by Mr Whippy]
Now I only hope to buy the right set of components to put together for new brake line...
Hi
Just working from your pictures when you do a female flare do you not do a male one first ? your pictures show stage 1 normal pipe stage 2 female
flare
Been a few years since i did it though.
Nick M
I had that tool. I bought a different one as I found it offset the flare on the pipe to one side.
If you hold the pipe vertical, then roll it through your fingers 360 degrees I could see the flare stock out further one side than three other.
If I could be so bold to hijack, how do you know what flare to do? My new tool is the one recommended on here years ago. It only seems to do one type
of flare. What is the concave Vs convex and how do you know when to do which one?
link to the current tool. https://www.carbuilder.com/uk/hand-held-brake-pipe-flaring-tool
quote:
Originally posted by nickm
Hi
Just working from your pictures when you do a female flare do you not do a male one first ? your pictures show stage 1 normal pipe stage 2 female flare
Been a few years since i did it though.
Nick M
quote:
Originally posted by MikeR
I had that tool. I bought a different one as I found it offset the flare on the pipe to one side.
If you hold the pipe vertical, then roll it through your fingers 360 degrees I could see the flare stock out further one side than three other.
If I could be so bold to hijack, how do you know what flare to do? My new tool is the one recommended on here years ago. It only seems to do one type of flare. What is the concave Vs convex and how do you know when to do which one?
link to the current tool. https://www.carbuilder.com/uk/hand-held-brake-pipe-flaring-tool
I wanted to finish the Fury during this weekend (4
days available due to Italian holiday) to go for body paint, that I accept any tip and extra money to be sure to correctly finish the brake line.quote:
Originally posted by MikeR
I had that tool. I bought a different one as I found it offset the flare on the pipe to one side.
If you hold the pipe vertical, then roll it through your fingers 360 degrees I could see the flare stock out further one side than three other.
If I could be so bold to hijack, how do you know what flare to do? My new tool is the one recommended on here years ago. It only seems to do one type of flare. What is the concave Vs convex and how do you know when to do which one?
link to the current tool. https://www.carbuilder.com/uk/hand-held-brake-pipe-flaring-tool
oh dear
I buy brake pipe from Halfords, its the - Product Type : Pipe Tubing 3/16
I use
Product Type : Pipe Union Male
Size : Male M10 x 1 Pitch
and
Product Type : Pipe Union Female
Size : Female M10 x 1 Pitch
your flaring tool is way fancier than my cheapo joby and it works just fine. I've used these on all my semi modern cars never having a leak and
only had to use imperial on the landrovers.
on brake hose ends they seem to need a double flare (like a cup) and other joints a bubble. If your not sure have a look inside the connection as its
quite obvious by the shape inside. I'd stay away from the SAE single which I think your showing there with the huge countersunk, that's
never going to squeeze down on the pipe hard enough.
quote:
Originally posted by Mr Whippy
oh dear
I buy brake pipe from Halfords, its the - Product Type : Pipe Tubing 3/16
I use
Product Type : Pipe Union Male
Size : Male M10 x 1 Pitch
and
Product Type : Pipe Union Female
Size : Female M10 x 1 Pitch
your flaring tool is way fancier than my cheapo joby and it works just fine. I've used these on all my semi modern cars never having a leak and only had to use imperial on the landrovers.
on brake hose ends they seem to need a double flare (like a cup) and other joints a bubble. If your not sure have a look inside the connection as its quite obvious by the shape inside. I'd stay away from the SAE single which I think your showing there with the huge countersunk, that's never going to squeeze down on the pipe hard enough.
As flexi pipe I mean this:
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quote:
Originally posted by 40inches
The counter-sinking on the nuts looks a bit excessive?
Just checks all my spares and they don't have any counter-sinking!
I have these CBS nuts
quote:
Originally posted by MadMaxx
quote:
Originally posted by 40inches
The counter-sinking on the nuts looks a bit excessive?
Just checks all my spares and they don't have any counter-sinking!
I have these CBS nuts
Are these nuts for DIN flare?
quote:
Originally posted by 40inches
quote:
Originally posted by MadMaxx
quote:
Originally posted by 40inches
The counter-sinking on the nuts looks a bit excessive?
Just checks all my spares and they don't have any counter-sinking!
I have these CBS nuts
Are these nuts for DIN flare?
They are M10x1, I have used them on SAE and DIN flared joints same as yours with no problem. The copper/Kunifer will
take the shape of the hard fittings.
Just to clarify, the nuts you have are for this fitting.
Convex female fitting
[Edited on 1-6-22 by 40inches]
I don't know for sure the different tool will fix your problem. Just saying I had a problem with the tool you currently have.
Sorry to stress again you all, but still very confused:
Old on left with flat top nut (SAE flare?), new on right with inside chamfered (DIN flare?).
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Old joint between kunifer pipe and flexible (imperial?) pipe to caliper:
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Old Imperial (?) T joint above and new metric Tjoint below. It really has different conical shape inside, specific for SAE or DIN flare?
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Wow this is a very confusing story!!
You need to start by identifying what is required at the various connections.
Start by identifying whether you need metric or unf - they are very similar, converted to metric 3/8 x 24tpi (UNF) is 9.5mm x 1.05mm vs 10mm x 1mm for
metric. It's very difficult to tell them apart by measurement, it helps if you have known good components to test with.
Then identify which type of flare is required eg single or double - single would suit your tee piece and double the front flexi bulkhead.
Then identify DIN vs SAE. However my experience of DIN vs SAE is the same as whippy, never had a problem, I'm not even sure what flare my tool
produces.
If you are not confident identifying metric vs imperial, single vs double and & sae vs din, you can always cut the nuts off the old pipe and reuse
them. At least then you can be confident of having matching components.
Hopefully you will get there.
Cheers
Davie
I often reuse the fittings simply getting them red hot with a blow torch and then dropping them into some old engine oil. come out looking very nice
and stained black. Don't heat the ends of hoses as they explode.
Screw the fittings together by hand with no pipe. They should go together with no play all the way to the bottom of the thread. If they don't
your mixing up threads. You need to take those chamfered unions and hurl them into the bin.
Look here's a pipe and flexi from my car. I only use these two types of fittings for the whole car. These are metric and you'll note there
is no chamfer. These have been split after fitting and you can see that the bubble has clearly been squished smooth and flatter, I can't see that
in your examples of the bubble.
[Edited on 1/6/22 by Mr Whippy]
Here's the same pipe end fitted to a metric t-piece, you can't mix metric and imperial as it just won't thread together. I can fit this
hand tight, note the thread has not run out so I know it is squeezing the bubble. Even hand tight I cannot blow air past it.
[Edited on 1/6/22 by Mr Whippy]
Just my observations on your pics,
The original on the left is a din type flare with no chamfer on the m10 nut, this is what you need to replicate. The flare on the right is not
fully/correctly formed, and is going inside the chamfer which is making the problem even worse.
It may be worth making some test flared sections that you can thread into place - with the nut fingertight, the pipe should not be loose in the
fitting and there should be enough thread left to allow the nut to be fully tightened ie at least 2mm of thread still exposed.
Once you can see what works, you can make your flares to match.
A generally used standard with brake pipe hardware is metric threaded parts are gold/yellow passivated finish, and unf threaded parts are plain zinc
finish, this only applies to zinc plated steel parts.
This should be a m10 female nut, with a double sae flare to match the end of the hose bulkhead fitting.
This pic from your archive looks fine and correct for this:
Description
Difficult to see here, technically the din flare has a 115° angle into a 120° seat , the sae flare has a 90° angle into a 96° seat. You could cut a
card template to check, but may be difficult to see this.
At a guess, the old tee union is a din fitting matching your other old fittings, and the new tee union is a sae fitting matching the chamfered brass
nuts you were supplied, both m10 thread.
The new fitting also looks to have machining chatter marks on the seat, this would make it hard to get a good seal even with the correct flares.
Other thoughts
-The flaring tool you have is only for sae flares, as others have mentioned, the copper is soft enough that you can get away with tightening a sae
flare within a din fitting, not best practice but it can work with copper pipe.
The pipes will need more tightening than usual in this case, again a test section is useful to know how much to tighten without damage.
I have seen overtightened unions fail, but only with sae double flares fitted using din nuts, where the square edge has cut off the flare from the
pipe - this is good reason to match correct components wherever possible.
-You need to get some decent din spec male tube nuts, i did look on ebay.it and found only suppliers in the uk, similar on amazon, have you got any
local car part stores who you could actually visit to match tube nuts to your original parts?
Alternatively, if.you have access to a scrapyard, cut off the matching fittings at the abs pump end of a few cars, these are unlikely to be corroded
and will be of good quality and the correct spec from any modern/european car.
-I have had a roll of copper line that would not make good flares due to it not being annealed properly, they always looked uneven and were difficult
to seal, it might be worth heating up a sample to anneal and seeing if it flares any easier/better.
Dave
quote:
Originally posted by MadMaxx
quote:
Originally posted by adithorp
Couple of things from those pic's (looking on my phone and a bit blurry zoomed in)...
The flare in pic 3 looks a bit small and in pic one the pipe might need to be further out before flaring to correct. Pic 2 looks like a double/concave flare and three a single/convex ? Pic 3 also seems to have some damage to the pipe behind the flare.
[img]
This is the photo of the nut I disconnect. Maybe some dents due to clamping of the flaring tool and a little flat end instead to be domed, so no chance to be pushed against the case by the nut? Should I have to check and smooth the contact surface, if needed?
My concern is that "all" joints seem suffer of the same problem so it should be some error in some point of the process of flaring or tightening, so my request of tips about to fix the problem.
