Bendy brakey pipes

[Pyoor_Kate]

So,

I've got to fit a new rear brake pipe (rear passenger side) - any tips? And um, do I need some kind of *tool* for bending brake pipes? Or can I just go bendy bendy?

And I believe if I just kinda lift that corner of the car up though magic faery power then I only have to bleed that one brake? Is that correct or am I madder'n a teapot?

Cheers m'dears!

[Multiphonikks]

So,

I've got to fit a new rear brake pipe (rear passenger side) - any tips? And um, do I need some kind of *tool* for bending brake pipes? Or can I just go bendy bendy?

And I believe if I just kinda lift that corner of the car up though magic faery power then I only have to bleed that one brake? Is that correct or am I madder'n a teapot?

Cheers m'dears!

I'm thinking kate that you'll have to bleed all your brakes... tis safer... And I know you hate it but...

[bigginger]

Yup, you need a tool to bend the stuff, (I have one if you want a borrow) and yup, really you should bleed the bleeding lot (then find out they're still spongy, and bleed them again, and again, and again, and again, and again... or is that just me?)
a
I've heard you can get away with only doing one but...

[Multiphonikks]

Yup, you need a tool to bend the stuff, (I have one if you want a borrow) and yup, really you should bleed the bleeding lot (then find out they're still spongy, and bleed them again, and again, and again, and again, and again... or is that just me?)
a

Andrew, it's not just you... I'm fighting that with Hebe

[bigginger]

Ain't it fun...
a

[Pyoor_Kate]

Nyargh. Can I just say I hate bleeding brakes. 'cos I really really do. I even hate it on the MZ and that's got one brake 'master' cylinder a single pipe and a twin-pot calliper. It still takes hours on that. Bah.

Now I'm going to sulk!

And then ponder how I'm gonna do this this weekend/before next week. Meh.

[guydenning]

or am I madder'n a teapot?

perhaps - but not as mad as toast, eggs or a box of frogs - so be grateful... mind you - you do work for the NHS don't you? mmm - well at least you know where the tablets are kept

[Arfron]

You don't need at tool/former for bending copper pipes . I re- newed the lot using careful bending with my fingers !!
A useful thing which nobody has mentioned --- use a brake pipe clamp on the rear flexible pipe THEN you only need to bleed the brakes from the clamped section ,to the rear bleed screws X2 !! You can use a mole wrench , but the Girling tool or other make , is better . Hope this helps a bit ?? Arfron
ps . the proper brake pipe clamp is a must in anyone's toolbox , saves a heck of a lot of time !!

[bigginger]

Hmm, never tried it, certainly worth a go. Do you remove the clamp and then bleed only the rear section and just hope no air's gone 'tother way? You've got to ask or you never find out...
a
PS yeah, I've managed with just fingers before, but the pipe bender makes for a much neater job, particularly for tight curves. I still do any long, gentle curves by hand.

[rayofleamington]

Shaping:
Firstly - if you use steel pipe you'll need a bender to stop it kinking when bending. Copper brake pipe can be shaped very easily by hand.
Take off the old pipe, and shape the new one to roughly the same shape, then tweak it when refitting.

Bleeding:
A brake pipe clamp will be a wast of time for this. You can't guarantee that fluid comes out of the other rear pipe so you 'may' have to bleed both rears.
After fitting the new pipe and bleeding that side - if the brakes seem perfect then don't bother doing the other. (I actually changed a m/c without bleeding at the brakes as I bled off at the m/c t-piece before tightening the pipes and the brake pedal was pefect)

Brakes should be bled every few years anyway so if yours haven't been done for ages, you may as well do it now. Bleeding helps keep the water content in the fluid lower and theoretically reduces brake fade (brake fluid with 3 or 4% water will boil at a temperature much closer to hot brakes than fresh fluid, so in theory old fluid is quite risky)

[Chris Morley]

I agree with much of the above - copper pipes are easy to shape by hand unless you have to do a very tight bend. As for bleeding I've found that you can usually get away with doing one wheel only. A tip I was given by an old hand to reduce brake fluid leakage was to first remove the m/c cap, then place clingfilm over the opening before replacing the cap and tightening it gently by hand.

It seems to help as I guess the fluid isn't pushed out of the m/c and into the pipes by the force of atmospheric pressure? Normally (as the m/c fluid level dropped)more air would enter the chamber through the hole in the cap, but the clingfilm makes the cap airtight. Unless anyone with a good grasp of physics can explain it another way?

[Arfron]

Having looked at the various hypotheses on brake clamps etc , I believe I come under heading of" old hand" . I put an article in Practical Classicss , about the use of clind - film to reduce fluid loss ; mostly on the Girling M/C on e.g. Marinas/ Ford 100E etc . ( Many moons ago )
Sorry Ray , I do not necessarily aree with you . Youu can use a brake pipe clamp to isolate an area of the hydraulics to prevent air pervading the system .: that's why they are made ! Though , I agree that a " belts + bracers point "- probably a good idea to give the whole system a flush -- but without the vast amount of trapped air , which could have been introduced . I rest my case Arfron

[57traveller]

Agree with you Arfron re clamps, they're not necessarily a waste of time and can save having to bleed the complete system. (another "old hand") I doubt the cling film is needed or even possible with the Minor's master cylinder by virtue of the thread configuration of the cap, the static head pressure from the reservoir is virtually nil. However on a "conventional reservoir it's an excellent method. Just a small point to remember if resorting to Mole grips or similar as a pipe clamp is to use a couple of pieces of wood inside the jaws to prevent damage to the flexible pipe from the jaw serations and it doesn't need much force to close off the pipe. A purpose made clamp is better.

[Arfron]

Thanks for that 57 traveller . No , I didn't use the cling - film dodge on the 1000 -- more up to date , I used an EasyBleed set-up + old tapped threaded cap etc . + clamps to put more force on areas that were stubborn !! See they are handy !
Come to think of it the letter I had published about the cling film dodge was in the ' Practical Motorist ' in the late 1960's , or early 70's ?? Tempus Fugit !! Arfron
Ps I forgot to mention about the use of bits of wood good thinking !!

[57traveller]

Yes methinks more than a couple of us use the modified spare filler cap and Eezibleed method. That LITTLE bit of extra constant pressure, I think, does usually help in dislodging that stubborn air bubble.

[bigginger]

I use one, but still find I have to bleed and bleed and bleed and bleed and...
a

[Chris Morley]

Arfron - my 'old hand' was called Dave and he gave me the clingfilm tip over 5 years ago - so who knew about it first?

I believe the clamp on the flexible hose would work, but at the risk of damaging the outer braiding and the rubber tube, especially if it were old and the rubber was starting to lose its elasticity.

I've always though it a pity that no-one incorporated a shut-off valve or stop-c0ck into the Minor's braking system (at the wheel cylinders) to reduce unnecessary fluid loss and to prevent air bubbles lodging in brake pipes. It would act like a bleed nipple but in reverse.

[Pyoor_Kate]

Okay guys, wish me luck. I've just realised my MOT is going to have to be *before* the Shepton Show; um, so I best do my brakes um, tomorrow. Really. And yeah. Mmm.

Rat biscuits. I do hate when I forget to do something important until late.

[57traveller]

The cling film "trick" has been around a lot longer than 5 years Chris. Personally I 've never had any success making a seal using that method and the fluid has just poured out anyway!

[rayofleamington]

Sorry Ray , I do not necessarily aree with you . Youu can use a brake pipe clamp to isolate an area of the hydraulics to prevent air pervading the system

The rear flexi is on the pipe between m/c and the T-piece. I don't see how clamping it would be any use as the T-Piece other brake pipe will be open to atmosphere anyway.
I never said they were a complete wast of time (sorry if you thought that is what I had meant ;-) ) - It just seems a waste of time for Kate's repair mwhich is what I said:

A brake pipe clamp will be a wast of time for this. You can't guarantee that fluid comes out of the other rear pipe

On the fronts - a different story and the clamp may be well worth using as the flexi links direct to the cylinder.
As for clingfilm across the m/c opening. that's a good idea if you want to remove a pipe for a hours / days as it prevents the reservoir from self draining out of the open section causing you to do a lot of additional bleeeding.
When changing a single pipe you should be able to do it with not much leakage from the system so the reservoir shouldn't get empty - as long as you have the new pipe to hand before starting the repair.