Brake lines - splice in sections, or make up whole new ones?

[fishnchipsx2]

So failed the MOT fairly miserably today, with just over a sheet of failures! 

All my rear brake lines are corroded, so I thought I'd have a go at doing them myself, as I always like to learn a new skill!  Got myself a (cheap ) flaring tool, pipe cutter, some copper brakeline, a bunch of unions, and some fluid.

However, working with hard-lines is all new to me, so I have a few questions...

Do you think it would be a better idea to:

A.  cut out just the corroded sections of line, and splice in new parts? 
...or...
B.  Go the whole hog and replace all the rear lines? (8v gti, so I have a bias valve...)

I understand that VW uses bubble flares.  If I take option A, should I use bubble or double flares?  And do bubble flares use different unions to double flares?

Any other helpful tips?

Thanks in advance for any help...
Calum. 

[Mr Blue]

replace the complete rear section while your at it. I got carried away and replaced the brake spash guards, fitted mk4 calipers. I should have dropped the complete rear axel and changed the axel bushes while I was working in that section. Probably worth checking while your there.

I think I mushroom flared mine (been a while). fitted the hard line. Then removed it and checked to see if the flared hole was still open and not crushed closed.

[Ben Lessani]

Got myself a (cheap ) flaring tool

Tut tut - buy cheap, buy twice!

The rear sections are a doddle to replace - the only pig is access and corroded lines.

You've got a few pieces,

flexi: calliper > beam
hardline: beam > beam
flexi: beam > floorpan
hardline: floorpan > bias
hardline: bias > master cylinder

I insist on buying on of these (http://www.comparestoreprices.co.uk/images/sy/sykes-pickavant-brake-pipe-spanner-11mm-x-13mm.jpg), it will make your life MUCH easier.

You may as well replace all the lines up until the bias, then you can just chop the pipe and put a socket over the union - dead easy then.

For the unions I was using, (single) bubble flair was what was needed (http://forums.pelicanparts.com/uploads12/double+vs+bubble+flare1201238131.jpg).

[fishnchipsx2]

Cheers Blue... I'm short on cash to say the least until December, so there won't be any new calipers or bushes going in just yet!  Also my parking permit conditions state 'no major repairs to be undertaken on site  " ... so dropping the beam might be pushing it a bit far - at least with the beam on, I can drop the car onto the wheels if anyone jobsworth comes sniffing around! 

Good stuff, cheers for that Ben:

All the flexis are braided hoses, so I'll be keeping them,  apart from one caliper hose, which is apparently leaking - although it may just be a case of tightening up. If not, is it possible to buy them singly?

However according to the friendly MOT man, all 4 of the hard-lines up to the compensator are corroded, so I'll be doing all of them...

Already got a flare-nut spanner, gotta agree that they put 'normal' spanners to shame! 

then you can just chop the pipe and put a socket over the union

^^Are you suggesting this purely for ease of access, or is there another reason?    Sounds good to me though...

Will get my longboard out and head down to the shop later on to see if I can swap my 'normal' (double-flared, I'm guessing?) unions for single bubble-flare ones...

Thanks for all the advice!

[Ben Lessani]

^^Are you suggesting this purely for ease of access, or is there another reason?    Sounds good to me though...

Yeah, it just makes it all a bit easier - it can be a fiddle with a non-ratchet spanner as there isn't much room to turn it, so its spanner on/spanner off ... spanner on/spanner off.

But if you just chop the pipe - you can just put a socket over it or ratchet spanner, considering you are replacing all the lines to the bias anyway, cutting them as close to the union will make it easier - plus you can gauge the pipe lengths and bends better with the big portion off the car

[mwep201081]

Replace the whole lot......Joins = leaks

[nealey]

I would just do the lot, the rest will corrode at some point so may as well just do it in one go now and save time and hassle further down the line

Also if you splice in sections then you increase the chances of leaks so imo its a no brainer really

[fishnchipsx2]

Will be doing all 4 at the rear then.  I have male unions, which I'm told will fit any single flare - including bubbles. Will get out there now to get started.

A question for later... when I bleed the brakes, I'll probably use the 2-person method, as it's worked well for me before.  Problem is, I no longer have the random bit of tubing I used last time to stick over the nipple and route into a jar of fluid.  Has anyone got any suggestions for what to use as tubing?  Washer hoses are just a little bit to small...

Having a problem getting the flare-nut spanner to fit over the n/s beam-flexi to caliper-hardline joint.  What seems to be a part of the bias valve linkage connecting to the beam is in the way... would disconnecting this help?  Cutting the pipe wont help as I can't envisage fitting a socket in there anyway, and although a normal 11mm spanner will just fit, I don't want to go down the route of rounded-off unions!

^^Please let me know if you didn't understand that, and I'll re-word/draw a diagram/take pics 

[Ben Lessani]

if its the one that is blocked by the arm for the bias that comes off the beam, i just removed it to get better access

[fishnchipsx2]

Safe, I'll remove it when I get on the case tomoro then, cheers!    (You do mean the part attached by 2x14mm (or mebbe 13mm, I canny remember) bolts+nuts, right?)