Replacing NS Rear Wheel Cylinder

Post by **bmcecosse** » Wed Aug 19, 2009 10:54 pm

The pipe must NOT twist !! The two part unions can be unscrewed together - provided they rotate on the pipe without it turning. But this is only possible provided the small union has been backed off enough by itself to release the formed end of the brake pipe - which it has trapped between the two unions. This is what forms the seal of pipe to solid cylinder ! Remember - as I said before - if you have to renew the rear axle pipes (and I'm sure you do) they have an unusal thread on the unions - of 3/8" BSF. Not every garage will have these unions - although you may be able to re-use the old ones if they come off in good condition - but I have to say that's not very likely!

Post by **xpress** » Wed Aug 19, 2009 11:07 pm

I promise you all that I didn't bend this pipe too much, I only backed off this bolt and realised I'd better stop and have a think.

Should this brake pipe be turning when turning the small union? Should the pipe be turning with it?

Post by **xpress** » Wed Aug 19, 2009 11:11 pm

Sorry bmc I have only just seen your thread, yes I am thinking these bits and pieces might not survive.

Post by **bmcecosse** » Thu Aug 20, 2009 8:49 am

Ok - NO - it must NOT turn with the union!
Two new pipes - one for each side, made from Kunifer if possible - with 3/8" BSF Male fittings - and Bob will be the Uncle!

Post by **jaekl** » Thu Aug 20, 2009 1:30 pm

bmcecosse wrote:The 'spring clips' are more usually called 'bee-hives' - and very few Minors still have them in place! Works fine without them.
The little 'bolt' as you insist on calling it is the UNION - and it unscrews like nearly every other bolt/set-screw/union etc ANTI-clockwise - as you look at the head. In this case - you are looking at the end of the union - not the head - so it appears 'clockwise' to you, but it will confuse others to say it unscrews 'clockwise' - the convention is to look at the head and unscrew anti-clockwise.
I agree with others - no point rushing this - although for most it would be a 1 hour job max! And yes -your brake pipes look to be in urgent need of renewal!!

A more universal procedure that applies wherever you are in relation to the thread is to use your hand as the name applies. 'Right hand thread' (most commone), wrapping your right hand and fingers around the threads in the direction of rotation, your thumb will point in the direction of movement. Used the other way, with your right thumb pointing in the direction of desired travel, wrapping your right fingers around the thread will tell you the direction of rotation. Those old technical guys were pretty clever with there naming systems.

Post by **xpress** » Fri Aug 21, 2009 5:28 pm

can anyone point me to a place that can supply kunifer brake pipe lengths for both rears, either pre-bent or not, with 3/8" BSF Male fittings? they have to be reasonably priced to suit my bargain hunting instincts! cheers.

Post by **ian.mcdougall** » Fri Aug 21, 2009 10:42 pm

Hi all
just started reading this post and I know it has gone past the stage of bleeding but if the car is up on stands and you release the unions to the cylinders no fluid will come out as cylinder is above master cylinder this is not true for all unions just look to see if above master cylinder or not
Regards Ian

Post by **xpress** » Sat Aug 22, 2009 1:48 pm

hi there ian, thanks for the heads up! i am going to try and turn this n/s rear pipe off from the centre rear union and then turn the wheel cylinder union out with the pipe and try to get it released while off the car!

(PS finding kunifer brake pipes isn't easy, most motor factors like to sell copper!)

Post by **xpress** » Sat Aug 22, 2009 1:51 pm

I found some kunifer, 25ft x 3/8" 30 quid plus 6 pounds to ship, anyone have a cheaper source?! also a cheap place for flaring, bending and cutting tools!

cheers.

Post by **xpress** » Sat Aug 22, 2009 1:56 pm

can someone explain to me how the flare works, or has a web page i could see for the arrangement of the flare and the union nuts?

Post by **MarkyB** » Sat Aug 22, 2009 5:54 pm

There is a good article here:http://forums.lr4x4.com/index.php?showtopic=10033
Uses the same tool that I have which came with a kit I think.
Basically you need to copy what is there.
The tool should come with instructions on how to make the different types.
From memory all the Minor ones are double flares.

Post by **xpress** » Sat Aug 22, 2009 6:48 pm

Conifer, conifer, my garden for a conifer!

Post by **bmcecosse** » Sat Aug 22, 2009 6:52 pm

No - they are NOT all double flares! Most are single flare - 1st Op.

Post by **bmcecosse** » Sat Aug 22, 2009 6:54 pm

In fact - some of these places selling 'copper' are selling Kunifer - they just' don't know it! If it's bright 'copper' colour - then yes, it's probably copper. But if dull 'brass' colour - it's likely to be kunifer.

Post by **xpress** » Sat Aug 22, 2009 7:07 pm

Ah that's interesting to know. Yea i can see how they might call it copper, to be honest i can't believe they are still selling copper brake pipe! should all be kissyfur, (kunifer, excuse bad puns).

Post by **xpress** » Sat Aug 22, 2009 7:09 pm

ONE DAY the mogoggie will be back on the roads again! You heard it heere first!

Post by **GeoffC** » Sat Aug 22, 2009 8:20 pm

What most motor factors describe as "copper" IS Cunifer, it's an alloy of copper, nickel and iron, hence the name CuNiFer. - Cu = Copper, Ni = Nickel, Fe = Iron. (I think the "Kunifer" spelling is a brand name/trade mark). I've NEVER seen or heard of pure copper being used for brake pipe - it simply isn't suitable.

3/8" diameter pipe is far too big for brake pipe, the 3/8" mentioned previously is the size of the thread on the unions, NOT the pipe diameter. You need 3/16" diameter pipe, I paid £9 for a 25 ft roll a few months ago. You can buy a flaring tool for less than £20 in Machine Mart, and a pipe cutter for less than a fiver from just about any DIY outlet. As for bending tools, you already have them - they're called HANDS!

Post by **bmcecosse** » Sat Aug 22, 2009 8:30 pm

Some places DO sell 'copper' pipe unfortunately - I urge people to NOT use it! The main problem is the tendency to work harden and crack - although that may take years to develop - it's really not a great idea.
I have a Draper pipe kit - which works fine as long as I completely ignore the Draper instructions - and just use common sense. Good revolving pipe cutter in Poundland! Should NOT use a hacksaw - makes rough edge and can leave small particles inside the pipe - which will work along to the seals.....

Post by **GeoffC** » Sat Aug 22, 2009 10:21 pm

I think the Clarke one I have (from Machine Mart) is a rebadged Draper kit - it looks identical. It's a bit fiddly to use compared to the "Professional" flaring tools, but it does the job at a fraction of the price, and isn't the sort of kit you use everyday, so I can live with its quirks. I agree the pipe cutter is pretty much essential as it's nigh on impossible to get a decent flare if the pipe isn't cut straight, although I have used a hacksaw in the past and seemed to spend half my time dressing the ends with a file before flaring them. Even with a pipe cutter, I always ream the ends and blow any swarf out.

Post by **d_harris** » Sat Aug 22, 2009 11:04 pm

Just an idea xpress - might be worth using the profile link at the top of the page to put your location in - there may be someone local who can help. If you are anywhere near here I'd be more than happy to come lend a hand - and I know there are others who would too!!