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nelmo

Brake Lines

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I've got a tiny leak in one brake line, at the join between the copper and flexible pipes (car not finished yet). I've tried several fixes but it's not having it.

 

I'm considering changing to a flexible line the whole way but just for that one side - is that OK? Or would I have to balance it and do the same for the other side or even all 4 lines? In other words, can I mix copper ant flexible lines?

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It shouldnt be difficult to fix the problem.

Maybe an olive has been squeezed too much, or the copper pipe has been deformed.

If It was mine, I'd order a replacement flexy pipe,

and if possible, cut off the very end of the copper pipe

to get a new start.

 

Post up a pic for more detailed advice.

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+1 for what Bob has said.

 

The likely hood is that the copper, kunifer, pipe has been deformed.

 

Did you make the solid pipes or were they bought in pre flared. Did you check that the pipe had the correct flare before you fitted it ?.

 

The chances of the flexi pipe being damaged is very slim.

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The flare on the end of a copper pipe work hardens with just one tightening of the nut. Take it apart and it may no longer be soft enough to deform and seal. So you have a reducing chance of getting a seal each time you undo and re-tighten it. If the end is the correct shape (male or female) and its still in good condition it would be worth annealing it back to softness with a blow torch, letting it cool, cleaning both mating surfaces and tightening it firmly. It may well seal just fine. No cost and five minutes of your time. Worth a try!

 

Nigel

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I did the original flare on the copper pipe myself (so could easily be the problem) but I have chopped off the end and done it again.

 

The problem is, the pipe is now on the car and filled with fluid, so access is tricky and I've got slippery fluid all over the place while trying to do the flare. The 2nd attempt was better than the first but obviously not good enough and I'm running out of copper pipe to keep chopping bits off. Also, having to keep bending the copper pipe up (so I can get the flare kit to it) is going to snap it soon or at least weaken it for the future.

 

Ian, I don't think the existing short length of flexi is a problem - I'm thinking of just replacing the whole run of copper pipe from MC to the caliper, with flexible pipe (so no joins, no leak). Can I do that on just one side (front nearside) without also doing the offside as well?

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at the join between the copper and flexible pipes

Exactly which join do you mean? is it at the body side panel?

 

Even if you do it all in flexy, isnt there a join where it goes through the body side panel?

I really dont know if you can replace just one side in flexy.

My gut feel is not to do it, for cost if nothing else,

If you have to take it through IVA. I can imagine all sorts of awkward questions

I would buy another length/reel of copper/kunifer pipe & make it up off the car.

Its easier then to check for correct flares etc.

You will need to bleed the brakes anyway even if you fit flexy.

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I did the original flare on the copper pipe myself (so could easily be the problem) but I have chopped off the end and done it again.

Are you sure you put the correct flare on the pipe, solid, copper pipe , to the flex needs a double flare making a concave shape to the pipe. a single flare leaves a convex shape.

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Yes, it is at the panel join.

 

I was thinking flexible only because the connections look far more secure and don't rely on me having to do a decent flare.

 

I don't think I did a double flare but I haven't got leaks on any of my other connections (so far, anyway) and I did them the same way.

 

I guess I could re-do the whole run off the car, as Ian suggested, but if I'm going to do that, I may as well go the flexible route, if possible (the extra cost isn't huge, I don't think?).

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I'd recommend speaking to your local SVA/IVA inspector to get his own personal view.

He will be testing your car & I reckon its best to ask exactly what he will expect to see.

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Why does it have anything to do with IVA? Flexible brake lines are not an issue and I can't read anything in the IVA manual that might be a problem - it just talks about materials and fixing points being of sufficient strength (it does say there can't be any leaks :-) ).

 

I was more concerned that maybe a flexible pipe on one side and copper on the other might provide a different level of pressure or something?

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If i understand the problem correctly, you have a female and male connection? and one is leaking even after tightening it? If so can you not use a crush (copper) washer

 

Reinforced flexi lines are nothing to do with IVA. Some people complain of a bit of flex in them. I cannot really say i noticed the difference between the hard line and the flexi lines. I have installed both in different cars

Edited by femster

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Yes, it is at the panel join.

 

I was thinking flexible only because the connections look far more secure and don't rely on me having to do a decent flare.

 

I don't think I did a double flare but I haven't got leaks on any of my other connections (so far, anyway) and I did them the same way.

Put on a picture of one of your flared ends -- or make a dummy just for the photo to show exactly what flare is on the rest of the car -- single flares will not hold pressure for long once on the road.

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Watched a video of making a double flare - definitely not what I've done. Bugger.

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Double flares are an absolute must on all brake pipe joints.

Sorry to be the bearer of bad news.

The flares with single forming can easily pull out from the joint and will not form a definate seal.

The idea of the double flare is that the pipe fittings will further form a fluid tight seal when finally fitted together and the joints are tightened.

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