Separating fixed & flexible brake lines - rear

[Jeemy]

Probably something everybody else knows off the top of their heads but I can't work this out from manuals, searching or other knowledge.

I am going to pull my entire rear wishbone shortly as part of my rear wheel/arch rebuild.

I need to remove the brake line from the wishbone. The Lotus service manual reads 'remove the brake line from the wishbone'.

Here is what I am talking about. After a little clean up there is a nut on the left just over 10mm, a round piece with a flat edge (calling this the 'body' until I find out what its called), a locking bracket that just holds it tamped in, which I have removed as it was spinning anyway, and then on the other side of the bracket at the right, an 18mm nut.

This marks the beginning of the flexible brake hose, which I am going to replace with a braided line - but more importantly, this needs to come off to deal with the wishbones.

I've tried everything short of extreme force - before I can apply such, can somebody tell me where it should be applied?

I've already tried gripping the joint body with mole grips and turning the large nut, I can't get a decent drip on the small nut as 11mm spanner spins, and 10mm spanner will not go on. I will file until it accepts a 10mm spanner if thats whats needed.

I just need to loosen it, take it out of the wishbone bracket and connect it back together for now; the flexi hose is clamped.

Then while the wishbone is being dealt with I can work out what needs replaced. It maybe even pushes out against the flat part of the body but then it still needs to be separated later, and I am scared to twist it too far to see.

Thanks in advance!

[Brit-Car-Nut]

Jamie: The hex nut behind the abutment and the cylindrical portion just after the clip are all one piece.

You remove the brake line from the cylindrical portion by holding the large hex part and use mole grips on the small line nut - Try to avoid destroying the line nut, but lines are easy to make.

Once you have removed the copper brake line, you pull the fabric line with the cylinder part back thru the hole and move on.

brake-line2.jpg

This is a new brake line end:

brake-line3.jpg

[DeeAitch]

Jamie, seeing as you are going to remove the wishbone then why not attack the inboard end first, it has to come off anyway?
Otherwise just flatten the metal pipe with a big mell, maybe turn it over on itself a few times to stop it leaking, then find your trusty hacksaw. Looking at those pipes you are going to need new ones anyway, relatively cheap and easy to make these yourself.
IIRC the 'all one part' Brit car nut refers to should have a flat on it, sort of D shape, to stop it turning?
Top tip. If your pasing mate holds the pedal half way down while your on with the mell you won't lose any fluid

[Brit-Car-Nut]

No flat on cylinder end, completely round.

[dapinky]

As Dave and John have said, but also a few extra thoughts.....

.....If you're fitting braided lines, then the current 'hard' lines (whether original steel, or newer copper/cunnifer/nickel) will probably be too short (by 1/4" each end) and you will need new ones anyway (only a few pence to get made up if you can't do it yourself).

Basically, worth doing anyway, even if the new ones fit exactly, as you will have new fittings to tighten up, which is far easier than using slightly knackered ones!


As you say, a 10mm doesn't fit, an 11mm is too big, and you end up rounding the nuts - it's basically a 7/16" AF nut, not a metric one, but with 'new' ones, an 11mm fits fine!

This is all a bit of an end product of mixing Imperial (USA) parts with metric (EU) parts in a UK design!!!

If you have a set of Imperial AF spanners, then you will probably find that the 18mm is really 11/16", and the other bit on the pipe is 5/8".

Basically, i'd suggest doing as Dave H says, cut the pipe aft of the pressure limiting valve and crushing it closed whilst you work in the archway, then make up new pipes - thats what I did, anyway.

[Jeemy]

@B-C-N:

Thanks so much, thats removed without too much stress!

I plan to make new line back to the next bracket at least, I think. This one is all wonky which doesn't inspire confidence.

@DeeAitch

The D-part does have a flat piece and will only turn once that tamped in bracket comes off, I put it back to give it more hold before I tried to separate the two once I knew where to exert pressure.

Outboard is off now…but just really because I wasn't sure how far I was going to go with this. I'm hoping to be able to change the wishbone and lines without lifting the car any further up, otherwise I'm going to need to start lifting the front too, its already quite angled and chocked and I've got jacks all over the back, I don't have enough tools to lift the front without sitting her back down a bit first……all I planned to do was test fit the hubs when I started! But then it wasn't worth doing that without testing some brake discs, then when I was waiting for brake discs I decided to do pads now, then rebuild callipers, and on it went…..now the shocks are out!

I don't have enough room to flatten the pipe just now, I don't think. If I can get that inboard end separated and reconnected easily and get enough purchase to loosen the bone then its going to come off now and just get swiftly reconnected once out of the bracket.

I need to buy parts anyway and don't have money til next week. But if I could get the wishbone off I could put the elbow grease in. I'll leave it as it is just now and come to it fresh tomorrow to decide what to do, I think.

Gut feeling is that there will be enough space to do this as is. It will be a bit tight breaking the wishbone bolts' hold but I think I can do it and get the bone out safely. I've found so far that the suspension bolts aren't anywhere near as tough to break as the engine ones were, as they have had some movement and flex ongoing.

Then I can work on extracting the bushes which will need some jiggerypokery. During that time I can bring the car back down at the back end and then get the front onto ramps before raising her a bit higher to refit it all.

[Jeemy]

Lots to digest….

But I think I have the right parts then! The reason I decided to put the braided lines on was after searching replacements, it looked like there are only full kits available, which contain 6 lines, and therefore the 6-line kit I got with my front brakes, included 4 fronts & 2 rears. So it seemed a good idea to neaten this part.

Here is a pic of the 3 lines I've got, I assumed the top one would replace the flex line we're talking about but then got worried when I saw John's pic, about the square end and the longer joint piece. But if thats the 1/4" that one loses, then it looks like I have the correct joint piece, its just shorter.

I'll grab a set of imperial spanners, I went through the loose ones I have but didn't have any of those. That should mean I can get the other bracket removed and then I'll look into how to get the copper brake line made up to the correct size while the wishbone gets stripped and treated.

I mean, there is a good 1/4" of give in these existing lines. If having them made elsewhere, would one have them made straight to the size one wants, and then do the pulling on the car to fit them? Or do you measure the angles and have them made, bent and threaded? Given the cheapness of the tools and line, seems like its best to do it yourself. Also seems like to thread them on, they are going to have to be straight to thread onto the preceding piece, then you bend in situ and then thread the next piece onto the fitted pipe…..I will really have 4 corners to do so I think I will attempt this.

I am reading as much as I can so I don't have to ask too many obvious questions, but am still grinding through manifold technology at the moment!

I have lots of pics to post on my thread but its a bit jumping from one job to another just now so I will post once each task is complete so its readable.

[Brit-Car-Nut]

Jamie: That is a new original part from Lotus so you will need to make new steel/copper lines to make up the missing length on the bulkhead fitting. There is a good write up on LEC. Just do a search and watch for entries from Dapinky and specky

[DeeAitch]

What I did, to many years ago to admit to was make up a few 'blind' ends, basically male or female couplings with short melled pipes which I then use to blank off any lines I disconnect.
You can buy proper end stops if you so desire, pretty much the same as domestic plumbing but smaller!
If you go for Red wine ( I do, always ) pipes then they come straight ,ish. Very easy to make yourself if you have the correct dies. Best to get hold of a pair of the pliers you can get to bend the tight radii you will need, makes a much neater job. Partco or maybe Halfrauds?

[GeoffSmith]

If you go for cuprinol pipes...

Does it do what is says on the tin?