48 replies to this topic

[dow62]

Might be going over old (recent) ground here but are copper brake pipes A, safe and legal ? or B, dangerous and illegal ?.Lots of people ( some well known names) selling copper as fit and more or less forget,. My wifes corsa failed mot on corroded a brake pipe, what the garage/mot station fitted sure looks and feels like copper, ie soft and bendy.

[minimissionary]

Brake pipes should be kunifer (copper/nickel I think), definitely NOT copper. I get the impression that a lot of places that sell them as copper are actually selling kunifer pipes.
Was it the actual pipes that failed, or the unions between them?

This is the best input I can offer, but I'm sure someone more knowledgable will be along shortly.

[dow62]

Excessive corrosion ( mot mans words ) to pipe, from m/cylinder to l/h front wheel.

[Mini 360]

Kunifer is the way to go. MUCH better wearing in the long run

[brad-the-bear]

as a mechanic, MOST garages use copper brake pipes when repairing/re-fitting as it it a lot easier to bend into shape and make the flanges for the unions, also they do not corrode, which is a bonus. car manufactures use nickel based pipe as it is cheap, but it tends to corrode if not greased or protected. and yes it is safe and legal. i tend to remove the old pipe, bend the new copper pipe into the same shape,then fit and double check the pipe for leeks (once bled) and if it is clear of the body so vibrations don't cause it to chafe and wear.

[tiger99]

Copper is very dangerous, and therefore illegal, because its use, like any other dangerous modification, will make your insurance invalid,as well as violating the Construction and Use Regulations. In the UK it does not need to be specifically outlawed, the fact that it is unsafe is quite sufficient, although in Australia it is explicitly forbibben. It is being sold by many people who should know better, including Minispares, and is putting quite a lot of people in serious risk.

Copper-nickel (kunifer is one trade name) is the correct stuff.

Copper does not have a fatigue threshold, unlike steel. Pressurise it a certain number of times and it will burst. You will get a number of emergency brake applications, or a much larger number of normal brake applications, but burst it will, well within the life expectancy of the average vehicle.

Kunifer is not as tolerant as steel of fatigue, so it needs to be clipped down well, with no flexing. But it will take an essentially infinite number of pressure cycles, and on balance, is safer than steel pipes, which corrode.

Aluminium is also not permissible, again due to fatigue, and stainless is just about impossible to flare without cracking, so it has to be steel or Kunifer.

[brad-the-bear]

... nobody has pure copper brake pipes

Edited by brad-the-bear, 18 December 2011 - 10:05 PM.

[brad-the-bear]

its just called copper brake pipe as it looks like copper lol

[tiger99]

Kunifer actually does not look like copper. Compare them side by side, and it is very obvious. It does not feel the same either. But as I said, copper is being sold, and used, by people who should know better. Pipe described as copper REALLY IS COPPER. Don't use it, ever.

brad-the-bear, I hope you have good public liability insurance. I fear that you are going to need it.

[zef]

Taken from the MOT manual.

B. Brake Pipes and Flexible Hoses 1. Check that rigid brake pipes are securely held and not free to vibrate. 1. A rigid brake pipe inadequately clipped or otherwise supported. 2. Check all accessible rigid brake pipes for a. fouling by a moving part a. fouled by moving parts b. kinks b. kinked c. chafing, corrosion and damage Note: To assess correctly the condition of corroded metal pipes, surface dirt might have to be removed. This might require light scraping with the Corrosion Assessment Tool ‘spade end’. Care must be taken not to damage any protective coating.
c. excessively chafed, corroded or damaged
Note: Chafing, corrosion of, or damage to, a rigid brake pipe so that its wall thickness is reduced by 1/3 (eg approximately 0.25mm for typical hydraulic brake pipe) is a reason for rejection d. repairs
d. inadequately repaired or with unsuitable joint fittings
Note: Repairs to the pressure lines of hydraulic brake systems are unacceptable unless suitable connectors are used. Compression joints of a type using separate ferrules are not suitable 3. Examine flexible hoses for signs of weakness under pressure with foot-brake fully applied. 3. A flexible hose bulging under pressure. 4. Examine all flexible hoses for 4. A flexible hose a. room to move as necessary without fouling any part of vehicle a. has insufficient room to move, resulting in fouling on any part b. kinks b. kinked c. stretching or twisting c. stretched or twisted
d. chafing or deterioration
Note: A hose should be rejected for cracking or chafing only if that is sever enough to expose the reinforcement. d. excessively chafed or deteriorated e. exposure to excessive heat e. exposed to excessive heat

No mention of copper being illegal. Please stop the misinformation. They may be not as good as the other forms of pipe but certainly not illegal.

[minimissionary]

Taken from the MOT manual.

B. Brake Pipes and Flexible Hoses 1. Check that rigid brake pipes are securely held and not free to vibrate. 1. A rigid brake pipe inadequately clipped or otherwise supported. 2. Check all accessible rigid brake pipes for a. fouling by a moving part a. fouled by moving parts b. kinks b. kinked c. chafing, corrosion and damage Note: To assess correctly the condition of corroded metal pipes, surface dirt might have to be removed. This might require light scraping with the Corrosion Assessment Tool ‘spade end’. Care must be taken not to damage any protective coating.
c. excessively chafed, corroded or damaged
Note: Chafing, corrosion of, or damage to, a rigid brake pipe so that its wall thickness is reduced by 1/3 (eg approximately 0.25mm for typical hydraulic brake pipe) is a reason for rejection d. repairs
d. inadequately repaired or with unsuitable joint fittings
Note: Repairs to the pressure lines of hydraulic brake systems are unacceptable unless suitable connectors are used. Compression joints of a type using separate ferrules are not suitable 3. Examine flexible hoses for signs of weakness under pressure with foot-brake fully applied. 3. A flexible hose bulging under pressure. 4. Examine all flexible hoses for 4. A flexible hose a. room to move as necessary without fouling any part of vehicle a. has insufficient room to move, resulting in fouling on any part b. kinks b. kinked c. stretching or twisting c. stretched or twisted
d. chafing or deterioration
Note: A hose should be rejected for cracking or chafing only if that is sever enough to expose the reinforcement. d. excessively chafed or deteriorated e. exposure to excessive heat e. exposed to excessive heat

No mention of copper being illegal. Please stop the misinformation. They may be not as good as the other forms of pipe but certainly not illegal.

In which case, you could use elastic bands for tyres. It doesn't mention anything about those either.
As posted above, copped simply isn't fit for purpose.

[tommy13]

I have seen copper fracture as a result of vibration when it is inadequately clipped. As Zef has pointed out it is not an MOT failure point provided it is clipped correctly. I have never heard of it being illegal in this country, but because of the way I have seen it fail I would, and only ever have used 90/10 cupro nickel products which is also easy to shape compared to steel tubing.

[tiger99]

Remember that the MOT does not state that the car is roadworthy. It only means that certain testable items were satisfactory at the time of the test. Other things which may be important on certain vehicles are not, and possibly can not be tested.

At the end of the day, anything used in a safety-critical application is either suitable or unsuitable. If it is unsauitable and not fit for purpose, it is covered by product liability laws, amongst other things. It does not specifically have to be listed in the VOSA rules for that to be so.

I think minimissionary makes that point rather well.

[tiger99]

tommy13,

You have no way of knowing whether the fatigue fracture was caused by vibration, or by pressure cycling. Most likely, both contributed to the failure. Even if you clip the copper down tightly (not leaving it floating in mid-air as an alleged mechanic here is advocating), the pressure cycles as the brakes are periodically applied will make it suffer fatigue failure in exactly the same way.

[tiger99]

This subject has already been debated here very recently. Note that it involved a split pipe, and splitting is the way they will fail due to pressure cycling. Vibration will make them snap.http://www.theminiforum.co.uk/forums/index.php?showtopic=210147