Replacing a rear nearside brake line.

should it be a bubble flare iso ?

Double flare.

My VVC has just failed on both rear brake pipes (to be fair, they have been an advisory for the last two years) so the car is currently sat on axle stands, all four wheels off and her unions and nipples soaking in plus gas. I have ordered stainless unions, 5m of kunifer and a new t-piece, just to be sure.

My question is this. The route that the brake pipe take is pretty torturous, and I'm guessing that at the factory during assembly, the pipes went in fairly early on. After a bit of a mooch under there, I was idily wondering why, when I fit the replacements, don't I just clip them to the rear subframe and save myself some time, swearing and scraped knuckles?

I'm sure there is a very good reason why not and I'm equally certain that someone on here will know it

If it is an F the subframes are on rubber mounts so move slightly in relation to the body. This of course means that the brake lines will be subject to stress and will eventually fracture.

hi, do not put the brake lines to the subframe as it moves with the shocks and it will be an MOT no go, it is a pain putting the rear pipes up behind the wheel arches but they will go in, agree to scrape the knuckles is part and parcel of the job good luck and let us all know how you get on.

there we are, a very good reason not to do that, which I hadn't spotted. Thanks to both.

YOUR WELCOME.:broon:

so, I cracked on and got this done. The original guide is excellent and I hope that I can add a few things that I did which might help someone else.

First off, all three of the pipes at the t-piece were rusted. In David's picture of the t-piece, the pipe on the left (as you look at it) goes to the left rear brake flexi, the pipe on the right goes to the right rear brake flexi. The remaining (bottom) pipe is the feed to the t-piece from the brake cylinder.

Given the state of mine, before I started the job I got onto ebay and ordered:-
1 x t-piece
6 x stainless m10 male unions
1 x stainless female union
5m of 6mm kunfor pipe.

I got the car up on stands, all four wheels off. I wire-brushed & soaked the four caliper bleed nipples, along with the t-piece & it's mounting nut and both ends of both flexis, in WD40. I did this every night for a week. I also had the roof rear section unclipped and the engine cover off, in order to get at the right hand rear pipe.

Come Saturday morning, my first task was the crack off the bleed nipples at all four calipers. I did this with a six-sided 11mm socket and a t-bar. No problems with any of them.

Next, I turned my attention to the rear brake pipes. Using a six-sided brake pipe spanner, I had a tentative go at the brake pipes where they meet the flexi's; to my pleasant surprise both came undone with no fuss.

Time to move on to the t-piece. After giving the t-piece mounting nut a thorough wire brushing, I gently undid it. It came undone easily, thanks again to a weeks' worth of WD40. As all three pipes were rusted, I cut theme with aviation snips and then eased out both the rear brake pipes. I also followed the feed pipe back under the car until I found good, rust-free pipe, and then I cut it there using a pipe cutter.

Next, I fitted the female union to the feed pipe under the car and then formed a double flare on this pipe. Then I made up a pipe with a male union at each end, to "splice" into the original pipe and run to the new t-piece.

Then it was the turn of the new left and right hand brake pipes. I used the tatty originals to provide a template for the new kunfor pipes, allowing for the amount I had snipped off one end. These were then fitted with female unions at each end, double flared, and then I put masking tape over the ends of the pipes to keep the crap out, while I manouvered them into place. Getting them into place wasn't as bad as I expected, it's a methodical job and a long-bladed flat screwdriver is essential for unclipping the old pipes, and then subsequently driving the new pipes back into the clips.

And that was pretty much it. I went round twice to make sure that all the new unions were tight, then bled the brakes. The whole job took about 4 hours and that included two tea breaks and I was taking my time. I accept that splicing a new section of pipe into the existing pipe might not be the best solution (following that 'feed' pipe all the way back to the brake cylinder would be the gold standard, I suppose) but it's a method I have used before and I'm confident in my pipe work ( I have previously worked on crane & plant hydraulics, so not phased with the pipework itself)

Sorry for the block of text and no pictures, I know a picture paints a thousand words and all that. On reflection, I probably didn't need all new unions and a new t-piece, but the whole lot was only £12, not exactly breaking the bank.