Jump to content

brake pipe union spanner


ThreeSheds
 Share

Recommended Posts

Hi,

I was replacing a steel brake pipe (with Kunifer :) ) and so I cut the pipe at the (male) flare-nut (union-nut?) so that I could use a hex socket on the nut. Unfortunately - even with that, the nut promptly rounded-off :angry: . Because of where it is - on the rear brake pressure limiter - I now have to remove this component so that I can try using a vice or something on the nut. Anyway - to take off the limiter, I now have to undo 3 other union nuts :o .

So my question is - should I bother with one of those special union-nut-spanner things (the kind that's like a ring-spanner with a bit cut out of it)... Are they any good?

Another thing I noticed is that my 11mm spanners are all a bit baggy on the nuts so I measured up and the nut is 10.9mm while the spanners are 11.15 to 11.22. Is THIS normal?

I have left all the other unions soaking in WD40 overnight and will have another go tomorrow.

TwoSheds

<confession>It's a bit off topic cos it's a Pug 406, but I think that the question is relevant - well it will be when I start the same job on my RRC...</confession>

Link to comment
Share on other sites

Try using 7/16" as this a bit smaller than 11mm. If the union doesn't feel like it's going to let go then I resort to mole grips or a small pair of stilsons straight away. WD40 will have little effect unfortunately as the pipe union is a compression fitting and if it's designed to prevent brake fluid leaking out then it's not going to let WD40 in. If there are no rubber seals to worry about, then a blow torch can make quite a difference. If you have ABS then make sure air doesn't get back to to the control unit - there are problems with bleeding an ABS system on some vehicles.

Les.

Link to comment
Share on other sites

I've found the correct union spanner to be a definite improvement over a normal open ended spanner, but on really stubborn unions (most of them on the series 3 were), I resorted either to attacking them with mole wrenches, or cutting the pipe and attacking it with a stilson with the brake cylinder held firmly in the vice, followed by replacing the pipes.

With the amount of pipes I had to buy, I probably should of bought a flaring kit and made them myself :angry:

Link to comment
Share on other sites

Firstly - thanks for the replies chaps!

I dug out an old 7/16, but it was baggier than the 11mm... Perhaps it's a bit too old... (or perhaps it's that 7/16" calculates out to 11.1125mm ;) )

Unfortunately the valve block almost certainly has seals within it and appears to be aluminium - so it would conduct pretty well, oh and I guess the final clincher on the heat thing is that the plastic fuel tank is about 2" away :o

I too didn't hold out much hope for WD40 - but I was finishing for the day anyway and I guess it can't hurt :rolleyes:

No ABS - no problem.

<rant> - I have been messing with cars for 40 years now and in all that time I don't think they have changed the design of brake pipe unions. And in all that time I have never yet had one just nicely undo. Surely some better way of joining brake pipes exists? Of course it does - banjos for one. I guess everybody uses this system because it's cheap...

</rant>

<rant2>

I wouldn't mind so much if this was on the RRC, but the Pug is my DD and the RRC is immobile; and being sans voiture is something I really didn't want. I spent an hour planning and rehearsing this job so that I knew that I had all the parts and tools - that the pipe would go where I wanted it too - that the flare tool would fit where I needed it to - EVERYTHING! Except thinking that I wouldn't be able to shift this dmnd stupid union. And in effect I suppose I even planned for that with the cut-the-pipe-so-I-can-use-a-socket thing...

bggr!

</rant2>

TwoSheds (both now immobile)

Link to comment
Share on other sites

Flaring kits appear to be cheap and useless... Or bloody expensive. I have had two of the cheap ones in the past* so this time I dug deep and (since the job would've cost over a hundred quid at the dealers) I spent over £70 on a brilliant one.

Anyone in Leeds area need brake pipes flaring you know where to come!

Stillsons I hadn't thought of - I'll have a shot at that tomorrow... Thanks :)

TwoSheds

* The first one broke first time I used it so I took it back and got a more expensive one. Then the 2nd one broke too :angry: . When I took that one back the man told me that they are not meant to be used on steel pipes... The one I have now specifically says for copper, copper/nickel and steel pipes.

Link to comment
Share on other sites

I've used them for over 30 years and well worth the money there are different types and sizes metric imperial and if you can still get them whitworth, the whitworth ones even now seen to fit better than he others esp. on older vechicle.

Undoing them i reckon is an art, once you hear the rust seal crack, use some wd 40 or peneration oil on the pipe close to he join, this avoids twisting the pipe as the union nut is undone

hope this helps

Link to comment
Share on other sites

I've used them for over 30 years and well worth the money there are different types and sizes metric imperial and if you can still get them whitworth, the whitworth ones even now seen to fit better than he others esp. on older vechicle.

Undoing them i reckon is an art, once you hear the rust seal crack, use some wd 40 or peneration oil on the pipe close to he join, this avoids twisting the pipe as the union nut is undone

hope this helps

Thanks for that - I'll take my venereal calipers and if they have imperial too, I'll measure up what they have...

Link to comment
Share on other sites

hi all,

try a good quality 11mm spanner,better than the cheap boot sale choclate spanner,

halfords have decent spanners,as good as snap on,but cheaper..

That's true - and it was a Halfords Professional spanner that I was using. I think that the problem here is twofold - one: they make these nuts out of chocolate, and Two: with them being hollow, the crush effect of the spanner has little to resist it.

I wonder if the fact that I was using a wall-drive socket was counter productive here - do wall-drives impart more crush per torque than normal sockets?

TS

Link to comment
Share on other sites

That's true - and it was a Halfords Professional spanner that I was using. I think that the problem here is twofold - one: they make these nuts out of chocolate, and Two: with them being hollow, the crush effect of the spanner has little to resist it.

I wonder if the fact that I was using a wall-drive socket was counter productive here - do wall-drives impart more crush per torque than normal sockets?

TS

wall drive just does what it say it works of the wall instead of the corners like most even try the opened end but i use my snap on brake pipe spanners which are open end but slightly thicker and has a longer leverage allowing u to keep equal progressive pressure on it and i have had no bother with even the worst

Link to comment
Share on other sites

wall drive just does what it say it works of the wall instead of the corners like most even try the opened end but i use my snap on brake pipe spanners which are open end but slightly thicker and has a longer leverage allowing u to keep equal progressive pressure on it and i have had no bother with even the worst

Best I could get was a Teng - I'll be going out in a few minutes to try it... I'll let you know how I get on..

TwoSheds

Link to comment
Share on other sites

Got a Laser one and it does the job nicely. I think the fundamental problem here is that your brake pipes were never designed to be a service item, especially if they're steel which is a real money-saving gem when it rusts out and you have no brakes!

I did find the Volvo (303) brake unions were good quality (as was everything on the axles) and came undone easily even after 30 years, but then as my mate said "When someone builds a truck with portals, cost is not their primary concern".

Link to comment
Share on other sites

Don't know if it will help 20 or so years down the road, but I put antisieze on all the nuts when I replaced my pipes during my rebuild. I put it on the pipe, where the nut contacts it, and on the threads, but made sure to keep it out of the inside.

Link to comment
Share on other sites

Well my new Teng flarenut spanner wouldn't shift the remaining unions - not even the ones that I hadn't chewed yet!

Heres the valve block on the car (with the remains of the original problem nut):

valve_block.jpg

So-o-o-o

I cut off one pipe at the valve block and managed to undo the remaining two at the other ends using a 4" mole-grip. I then transfered the block to the vice where I was able to remove the (cut-off) unchewed one with the moles:

nut_removal.jpg

But the other one (which is seized into an M12 adapter, and was the original problem) would only come out after I drilled the middle and used a large stud extractor. I had a 10" adjustable on the extractor and I reckon I put on a good 50ft-lbs to shift it :o

using_stud_extractor.jpg

Anyway - I now have the block off and all unions that need to be-parted. So tomorrow it's off to get an M12x1mm 3/16 union to replace the current nut/adapter setup, and then we're on the homeward stretch - no more surprises I hope!

Here is a comparison between a normal M10 flarenut and the butchered M10-in-an-M12-adapter that I took out (and will be replacing with a straight M12 flarenut)

compare_to_new.jpg

BTW - anyone know offhand what torque should be used on flarenuts?

TwoSheds

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy