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Brake 4 and 3 way leaking issues, how do i stop the leaks?
The Venom Project - 24/12/10 at 02:02 PM

Hi All,

After a problem on my MNR in April with brake fluid leaking at the 4 way and 3 way brass joints, I wondered what other people were doing to combat this?

I had thought initially it was my flare tool, but even when MNR had made the pipes up, they still leaked.

I ask because come the new year, I will hopefully be starting a build again and will no doubt come across the issue again.

I thought they were not tight, but after stripping the brass thread with making them as tight as possible and it still leaking I was unsure what to do next.

Does it matter if you use Metric over Imperial brass fittings? I wasn't sure that the plated unions were good enough? Wasn't sure if they were seating correctly either. Does anyone use Gas tape to seal them? or any other type of sealing method?

Any help would be most appreciated

Merry Xmas to all

Nick

mistergrumpy - 24/12/10 at 02:09 PM

I've used PTFE on a couple of my joints and had no issues. CKC recommend PTFE too but a few on here won't agree. Their take is find the fault and fix it, which I think is easily said than done when you chase it for months and months on end.
You're probably aware that there are differnt grades of PTFE but most are unrective.
I'm sure I'll get flamed for writing this!

The Venom Project - 24/12/10 at 02:12 PM

quote:
Originally posted by mistergrumpy
I've used PTFE on a couple of my joints and had no issues. CKC recommend PTFE too but a few on here won't agree. Their take is find the fault and fix it, which I think is easily said than done when you chase it for months and months on end.
You're probably aware that there are differnt grades of PTFE but most are unrective.
I'm sure I'll get flamed for writing this!


To be honest, I saw no other way of stopping the leaks. I didn't get chance to use this method as my car died on the rolling road, maybe that was a good thing eh?

Cheers, I will of course try the old method on the new kit, but I reckon ~PTFE or something similar may have to be used, because if you have it as tight as it can be, how do you stop it leaking?

Many Thanks

Alan B - 24/12/10 at 02:17 PM

No flames...but PTFE tape (or sealant) is for taper threads only...where the sealing is actually done by the threads (sometimes there are taper threads in brake systems, but not often)....parallel threaded fittings do not seal on the threads and should never be used with tape.

As much a pain as it is, you really should fix the problem...not do a tape bodge...

Just my opinion of course..

Happy Christmas everyone

The Venom Project - 24/12/10 at 02:22 PM

quote:
Originally posted by Alan B
No flames...but PTFE tape (or sealant) is for taper threads only...where the sealing is actually done by the threads (sometimes there are taper threads in brake systems, but not often)....parallel threaded fittings do not seal on the threads and should never be used with tape.

As much a pain as it is, you really should fix the problem...not do a tape bodge...

Just my opinion of course..

Happy Christmas everyone


If you make everything so tight that it strips the thread, and it still leaks, what is the solution?

I have thought I may invest in a Venhill braided hose and cable kit instead of brake pipe, and use alternative fittings in that kit?

I am quite clearly not the only person with this issue, whether its a crappy Brass cast who knows. What do you use in the USA on Kits? What have you used on that car in your pic?

Does it weap? or leak at all?

Cheers

Nick

daviep - 24/12/10 at 02:26 PM

quote:
Originally posted by mistergrumpy
I've used PTFE on a couple of my joints and had no issues. CKC recommend PTFE too but a few on here won't agree. Their take is find the fault and fix it, which I think is easily said than done when you chase it for months and months on end.
You're probably aware that there are differnt grades of PTFE but most are unrective.
I'm sure I'll get flamed for writing this!


Where exactly do you even put PTFE tape on a flared connection? I can't believe that CKC would recommend using PTFE if it's picked up at an MOT it's a definite fail.

As per the last time you aked this question please try and get some detailed pictures of all the components so that informed diagnosis can be made.

Davie

The Venom Project - 24/12/10 at 02:27 PM

quote:
Originally posted by daviep
quote:
Originally posted by mistergrumpy
I've used PTFE on a couple of my joints and had no issues. CKC recommend PTFE too but a few on here won't agree. Their take is find the fault and fix it, which I think is easily said than done when you chase it for months and months on end.
You're probably aware that there are differnt grades of PTFE but most are unrective.
I'm sure I'll get flamed for writing this!


Where exactly do you even put PTFE tape on a flared connection? I can't believe that CKC would recommend using PTFE if it's picked up at an MOT it's a definite fail.

As per the last time you aked this question please try and get some detailed pictures of all the components so that informed diagnosis can be made.

Davie


Cheers Davie,

Well I will post pics if I encounter this issue again, does everyone still use the 3 and 4 way Brass units for brakes?

Is there not something nicer to use on the market?

Nick

daviep - 24/12/10 at 02:29 PM

How tight did you make the unions when you first tightened them?

They don't really need to be very tight and if overtightened can distort causing them to leak, only remedy is to cut off and re flare.

Davie

The Venom Project - 24/12/10 at 02:33 PM

Just looking for alternatives to plated connections, I see they do make Brass ones, do you think this is a better idea instead of Plated ones?

I would have thought brass to brass might be a better idea?


I appreciate say that PTFE is not the cure, but if you have checked everything and even the manufacturer can't stop the leak, where are you meant to go?

Cheers

Nick

P.S I will post pics if it does it again, but I may go down the Brass all round way as the other way first time round was not a solution

prawnabie - 24/12/10 at 02:35 PM

If it is happening on all the connections to the unions are you sure you haven't mixed 3/8 and 10mm fittings?

The Venom Project - 24/12/10 at 02:35 PM

quote:
Originally posted by daviep
How tight did you make the unions when you first tightened them?

They don't really need to be very tight and if overtightened can distort causing them to leak, only remedy is to cut off and re flare.

Davie


Initially they were nipped up with the ring spanner, it was only when I came to bleed them did I see an issue, on all points front and back.

I started at the back, and the pipe coming down into the 3 way I made tighter and tighter until it stripped.

I know MNR still had issues with this as it went to the rolling road, I am not sure how they fixed it, however I could ask Indybird what he found when it was stripped down.

CHeers

Nick

RichardK - 24/12/10 at 02:38 PM

I reckon you've done them too tight, I did all mine handtight then about half a turn with 1/8 further turns until they stop seeping if necessary. Which are leaking the bullet shaped end or the double flared end?

Cheers

Rich

The Venom Project - 24/12/10 at 02:38 PM

quote:
Originally posted by prawnabie
If it is happening on all the connections to the unions are you sure you haven't mixed 3/8 and 10mm fittings?


I had a nasty feeling about that initially, but then when MNR still had the same issue, I assumed this was not it.


From past experience, I never had any type of issue like this on old cars, I was very upset that each point bloody leaked :-)

The Venom Project - 24/12/10 at 02:39 PM

quote:
Originally posted by RichardK
I reckon you've done them too tight, I did all mine handtight then about half a turn with 1/8 further turns until they stop seeping if necessary. Which are leaking the bullet shaped end or the double flared end?

Cheers

Rich


They were all bullet shaped ones, all the points into the brass ports. The double flared ends were fine :-)

RichardK - 24/12/10 at 02:44 PM

Strange, I found those the easiest to do, I'd make sure that there isnt a ridge caused by the two halves, if so, run a fine file over to remove the ridge. and then I smear a tiny bit of coppaslip on the back of the neck of the flareso the fitting slides around it a bit easier while tightening.

Hope you get it sorted mate.

Cheers

Rich

rusty nuts - 24/12/10 at 02:49 PM

Sounds like the wrong flare / pipe nut or union . In 43 years in the motor trade I can honestly say that I have never had a leak on a correctly made union. PTFE tape is a bodge and should fail an MOT . Was a metric flare used or an imperial?? as the flares are a different shape. A UNF fitting is slightly smaller than a metric one and may be the cause of your problem?

The Venom Project - 24/12/10 at 02:53 PM

quote:
Originally posted by rusty nuts
Sounds like the wrong flare / pipe nut or union . In 43 years in the motor trade I can honestly say that I have never had a leak on a correctly made union. PTFE tape is a bodge and should fail an MOT . Was a metric flare used or an imperial?? as the flares are a different shape. A UNF fitting is slightly smaller than a metric one and may be the cause of your problem?


Many Thanks,

I think I may have them all professionally made by my local garage for my next build.

That way, they will get the right pipe size, right flare, right end, I reckon I am onto a winner

If I just measure what I need, hopefully I can't lose if I take the 3 and 4 way units to him.

Cheers

Nick

whitestu - 24/12/10 at 03:00 PM

I'm surprised - I made all my pipes with a cheap crappy Machine Mart tool and only had one leak which was fine when I redid it, and if I'm honest I'm not very good at doing them.

Are you sure the parts you are using are all the same?

Stu

The Venom Project - 24/12/10 at 03:04 PM

Hiya,

I must stress, this was an issue with my MNR, but I look forward to new things with my TR1KE, I may never encounter this issue again.

I can't say for sure all the bits were correct when I did it, but when it was re-done at MNR it still leaked.

However I think in light of the fact I had this issue, I will indeed get my local garage to make them, I too bought a cheapish tool after I had the issues, but initially I used a very expensive SIP brake pipe making tool, that I had used when I worked in the motor trade back in 1990, and never had issues back then,

Anyway, I hope this issue doesn't arise with my new build

If so, I will be back on with leaky leaky pics

Cheers

Nick

big_wasa - 24/12/10 at 03:19 PM

I bought the best tool I could aford and none have leaked.

britishtrident - 24/12/10 at 03:57 PM

Make the flares properly and use the correct tube nuts with the correct length of thread ..

[Edited on 24/12/10 by britishtrident]

gavin174 - 24/12/10 at 04:02 PM

contact Russ Bost

he can make complete brake lines with stainless fittings..

http://www.furoreproducts.co.uk/7_hel

The Venom Project - 24/12/10 at 04:04 PM

quote:
Originally posted by gavin174
contact Russ Bost

he can make complete brake lines with stainless fittings..

http://www.furoreproducts.co.uk/7_hel


Many Thanks,

I will contact him in the new year and discuss prices.

Cheers

Nick

ashg - 24/12/10 at 04:32 PM

could possibly be crap t fittings. I had a similar issue on a 3 way one, eventually used the 20year old one the was off the sierra and the problem went away.

britishtrident - 24/12/10 at 08:10 PM

quote:
Originally posted by ashg
could possibly be crap t fittings. I had a similar issue on a 3 way one, eventually used the 20year old one the was off the sierra and the problem went away.



Ford use short tube nuts the after market type require tube nuts with a different end and a longer thread these are used by many other manufacturers including Vauxhall/Opel.

[Edited on 24/12/10 by britishtrident]

ShaunB - 24/12/10 at 11:32 PM

Following on from britishtrident I once tried a union that was too short to push the pipe flare onto the union seat but in this case it was pretty obvious as I could push/pull the pipe in/out about 1mm. A longer union sorted it. I wonder if your unions are bottoming out just before they are able to apply sufficient pressure to seal the joint - how much thread can you see when they are done up?

Shaun.

The Venom Project - 26/12/10 at 07:55 PM

I had the longer ones, so lots of thread left showing, well at least 4-5 threads anyway, I can only put it down to poo fittings, as although some people have had the same issue, its quite clear that others haven't.

I think I will go for all Brass this time, and take my fittings and calipers etc to my local garage to make sure they are done right.

I don't need many anyway, I need 2 x front ones, and one from front to the rear wheel, so I only need a 4 way at the front as its a reverse trike.

Cheers

Nick

chris666 - 28/12/10 at 10:24 AM

Under what criteria could the mot tester fail the ptfe tape?.As far is i know if there is no leaks,and the performance is met, there is no reason for a fail.I had a similar problem on my brake pipes.it was all down to a poor flare and overtightening of the union.

Chris