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Weaping 3 and 4 way Brake blocks
The Venom Project - 13/1/10 at 11:58 AM

I have a slight weap on all points where my barke pipe unions screw into the brass 3 and 4 way units, I am using Kunifer pipe flared onto plated (Not Brass) unions and then these are tightened into the brass 3 and 4 way units, I have got them as tight as possible without stripping the threads. Any ideas? Any advice on how to stop this? I am pretty sure this will be a fail on IVA if its spotted

Anybody else had this?

Cheers

Nick

Alan M - 13/1/10 at 12:09 PM

It will not only fail but it's potentialy lethal!
When making the flares you need to clean the burrs off the cut pipe first with some emery and make sure the cut is square, or better still use a pipe cutter. Have you put the right flare on the pipes?

Mr Whippy - 13/1/10 at 12:10 PM

take the joints apart and inspect the flange faces for scores, marks or grit that may be preventing the surface sealing

would be happier if you posted some good close up pics of the flanges you made tbh

[Edited on 13/1/10 by Mr Whippy]

daviep - 13/1/10 at 12:11 PM

If they are tight and still not sealing then there must be a problem with either the flare on the end of the pipe or the union.

Are the flared to suit the union you are screwing them into eg. convex or concave?

Are the flare nuts the correct thread?

Have the flare nuts bottomed out in the union?

Do the flared ends look correctly formed?

Pictures of all three individually and assembled might help.

Regards
Davie

The Venom Project - 13/1/10 at 12:29 PM

I used a pipe cutter to cut the kunifer, I did use to make them when I worked in the motor trade so I was pretty confident they were made right. The 3 and 4 way splitters are female thread so I went with male thread unions Plated with the correct flare that sits flush bullet shaped, I cannot remember which one it is, Does it make any difference if I use Brass unions with brass 3 way units? The unions I have are plated not brass. They do not bottom out , they all have some thread showing so I know they are tight.

I am happy to accept that the brake pipe flaring tool was not the best one I have ever used and the die may have been pitted. But I thought I had sanded it smooth to make a good seat on the 3 way.

I will get some pictures on this thread on Thursday as this is the next time I will be there.

Many thanks for the replies.

Bluemoon - 13/1/10 at 01:42 PM

Pitted die might be the problem? The matting surfaces should be a good fit before the nuts done up, only a small amount of deformation should occur when you do the nut up tight (and then not all that tight), if you have had to smooth the die you might not have the correct shaped surface, hence the leak???

Dan

bassett - 13/1/10 at 01:46 PM

Are these MNR supplied parts or your own as the kit i bought was roughly cut to the correct length with all the unions etc supplied. If not it may be worth buying there supplied kit as the flares were excellent. Is it leaking from the thread or where the nut fits over the pipe section? could possibly use some thread tape as i have some on the final threads where i had to use an adapter into the wilwood calipers for a 1/8npt thread and this works fine.

02GF74 - 13/1/10 at 02:19 PM

quote:
Originally posted by The Venom Project

I am happy to accept that the brake pipe flaring tool was not the best one I have ever used and the die may have been pitted. But I thought I had sanded it smooth to make a good seat on the 3 way.


sanded?!?!?!?

the pipe would normaly be convex i.e. a little cone on the end - the fitting pushes it into the concave block, the pipe metal copper or kunifer is easy to squeeze so it should really seal.

bit hard to see where the problem is without any photos.

britishtrident - 13/1/10 at 02:39 PM

The standard Metric flare is a convex "bubble" single flare. The double flare convex-concave is commonly used but is non-standard, if this is the type required it can be spotted by examining the internal of the whatever it has to be screwed into.

Usually problems with getting seals on flared joints are usually due to the flare being too small.

Also the tube nuts exist in two different thread lengths if the short thread and long thread fittings are mixed up you won't a seal.

daviep - 13/1/10 at 03:48 PM

quote:
Originally posted by bassett
Is it leaking from the thread or where the nut fits over the pipe section? could possibly use some thread tape as i have some on the final threads where i had to use an adapter into the wilwood calipers for a 1/8npt thread and this works fine.


PTFE tape should only be used to seal tapered threads such as npt and bsp where the seal is created on the threads, flared connections do not seal on the threads and should not require additional sealants.

Looks like you're going to have to strip them out and have a look. The fact that all your connections suggests there is something fundamentally wrong.

Regards
Davie

The Venom Project - 13/1/10 at 05:13 PM

quote:
Originally posted by bassett
Are these MNR supplied parts or your own as the kit i bought was roughly cut to the correct length with all the unions etc supplied. If not it may be worth buying there supplied kit as the flares were excellent. Is it leaking from the thread or where the nut fits over the pipe section? could possibly use some thread tape as i have some on the final threads where i had to use an adapter into the wilwood calipers for a 1/8npt thread and this works fine.


Its leaking down the thread, I defo think the tool I used is knackered as someone else pointed out that all of them bloody leak. Arghhhh, thats gonna be a fun job to do now the car is built. Thank god I cut a section out of the floor panel to get access.

The Venom Project - 24/1/10 at 01:24 PM

quote:
Originally posted by daviep
quote:
Originally posted by bassett
Is it leaking from the thread or where the nut fits over the pipe section? could possibly use some thread tape as i have some on the final threads where i had to use an adapter into the wilwood calipers for a 1/8npt thread and this works fine.


PTFE tape should only be used to seal tapered threads such as npt and bsp where the seal is created on the threads, flared connections do not seal on the threads and should not require additional sealants.

Looks like you're going to have to strip them out and have a look. The fact that all your connections suggests there is something fundamentally wrong.

Regards
Davie



Cheers for the info, I am gonna have a go at making new ends this week, and see if this does the trick, the other alternative is to pay MNR to do this for me, but if I can fix it myself I really need to. I feel though due to doing all the pipes when the body was off and engine out, that this job just got much much harder. The pipes going from the brass dividers will be easy enough as I can easily remove them, but the one that goes front to rear 3 way, hmmmm thats gonna be fun, it neatly goes around all the tubes, around the diff etc:

SHITE comes to mind, and me thinks it wont be that neat again this time round :-)

bassett - 24/1/10 at 01:29 PM

dont worry you'll never see it again once its done

Wheels244 - 25/1/10 at 10:04 PM

Might be a silly question but have you tightened them as much as you can ?

I had to tighten mine F T to stop them leaking - I thought I was going to strip the thread

Worked though

[Edited on 25/1/10 by Wheels244]

The Venom Project - 25/1/10 at 11:19 PM

quote:
Originally posted by Wheels244
Might be a silly question but have you tightened them as much as you can ?

I had to tighten mine F T to stop them leaking - I thought I was going to strip the thread

Worked though

[Edited on 25/1/10 by Wheels244]



I tightened the rear one so much it did strip the thread :-) I then had to clean it up and just make it as tight as I could.

The good news is that today of all days as its my Birthday I finally got my car on its wheels....

Wheels244 - 27/1/10 at 08:23 PM

quote:
Originally posted by The Venom Project
quote:
Originally posted by Wheels244
Might be a silly question but have you tightened them as much as you can ?

I had to tighten mine F T to stop them leaking - I thought I was going to strip the thread

Worked though

[Edited on 25/1/10 by Wheels244]



I tightened the rear one so much it did strip the thread :-) I then had to clean it up and just make it as tight as I could.

The good news is that today of all days as its my Birthday I finally got my car on its wheels....


B*gger !

Oh well - happy birthday - great present getting it on it's wheels

G.Man - 31/1/10 at 05:21 PM

I had the asme problem with mine, only way I could get them to seal was with ptfe tape.

I hear what is said above, but ptfe worked for me.

The Venom Project - 31/1/10 at 06:30 PM

quote:
Originally posted by G.Man
I had the asme problem with mine, only way I could get them to seal was with ptfe tape.

I hear what is said above, but ptfe worked for me.



Yeah I hear ya, my last solution before PTFE tape is to remake the pipes with a proper new brake pipe tool, I shall try this first I think. Also my front 4 pot calipers purchased from MNR seem to leak too, I hate brake fluid :-) I have put a copper washer before and after the brake screw going into the caliper. Is this correct? My dad seemed to think it needed a copper washer on both sides of the bolt to seal correctly, all I seem to get is leaky brakes., Handbrake works fine, maybe I can just use this? :-) Will be like driving R/C cars again.

G.Man - 6/2/10 at 02:46 PM

If the 4 pot calipers are Raceleda, I think they need the hole retapping to M10, check this with Marc tho first!