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MG MGA - Bubble Flare or Standard Flare Brake Lines

While installing new steel brake lines in my Coupe I came across something I find "strange". I bought a complete kit of brake lines from Automex,(copper lines)and all of the flares on this kit are "bubble flares". I installed the kit with no trouble, only to find out that when I will be going for inspection,that copper lines are illegal. So I started the process of replacing them.

All of the front brake cylinders are bubble female fittings and everything went smoothly while installing the new steel bubble flare lines .At the rear, I came across the problem. For some strange reason,the 3 way brass union has the following:

The fitting for the rubber brake lines is bubble flared, while the fitting for the hard steel lines are standard flare. Further inspection shows that the rear brake cylinder banjo connections are a combination of standard flare (to receive the hard line) and bubble flare (to receive the bleeder). This has caused me to scrap one good brake line and a couple of hours of work. So....I ask ,can anybody explain why the combination of the two type of flares and why did the copper bubble flares "fit" when the hard steel won't.

PS: marked on the 3 way unit is: where the rubber hose mounts (UNF) and where the hard lines mount (EW). What does EW mean? Is this the same thing for the front 4 way union? Thanks Gord
Gordon Harrison

The Automecs lines are not copper, they are copper nickel, and they should be legal.

Copper lines would be too soft and I can understand why they would be illegal.

dominic clancy

Early 1500 have a different thread for some of the rear lines. I believe the lines from the 3-way to the wheels cylinders has Whitworth threads. The Moss catalogue shows a different set for early cars.

There are no DOT standards for copper nickel lines. I went through this a few years ago and had to get the recommendation of a Motor Vehicle engineer in another province. His explanation was that while some high end auto manufacturers do use copper nickel, you have no way of knowing what their material specifications are, and that the generic material from an independant supplier has never been tested. The high end manufacturers submit the entire car for testing and DOT approval and the responsibility for suitability of materials rests with them, not a DOT material approval. As a result the approved standard is "the same as original equipment".

In my case, while I got a verbal OK, the second tester didn't even notice them.
John

John
My understanding (now) is that the cop/nik lines are "not acceptable" anywhere in Canada. The question of an antique car rebuilt to spec is in the hands of the inspector.He may question them or he may say nothing. Rather than installing a complete cop/nik system and the fluids and having it rejected, I have chosen to replace the lines with steel ones.
The lines I bought are a major supplier (the type you buy in any auto store ) and I can only guess that they me DOT standards. I do know they "WILL" pass inspection.
As for the rear lines (with different flares), are you aware why they did this. It seems like an awfull lot of extra work for nothing. They could have continued with bubble flares throughout.You say Whitworth threads. My goodness it was hard enough to find a local supplier with metric fittings, let alone British fittings.

John or Dominic

Do you have any idea what the designation (on the 3way union) EW represents. I looked on the internet and the best I got was some type of brake lines for Land Rover.At least they are British.
Gordon Harrison

Gordon
Can you just salvage the threaded fittings from the copper lines and install them on steel lines? I can't remember the shape of the flair end. I don't think anyone would object to brass fittings. I recall calling Moss and SF about this to see what I could find out about their cup/nic lines. SF gave me the name of the fabricator, some garage in England.

Personally, I would prefer the cup/nic.
John

Hi Gordon. I live in Ontario Canada. Steel brake lines rust away, often from the inside out. This is extremely dangerous, particularly with a single hydraulic braking system as on our MGA's. I have recently purchased new automec copper nickel brake lines, and intend to install them this summer. Personally, I would leave the copper/nickel lines on your car, as they will not rust and are actually superior to steel lines, period. As for the inspector, he probably would not even notice the difference, since the copper nickel lines have a bright steel like finish. If asked, you could fib, and say you "think" that the lines are stainless steel. OR, You could coat all your brake lines with a light coating of grease, and then let a bit of road grime adhere to the grease. This way, the lines would be "disguised" a bit. In my opinion, beaurocratic bullsh*t (pardon the language) should have no authority when automotive safety is a priority! Personally, I dont think that the copper nickel lines would actually be considered illegal in Canada or anywhere else for that matter, since they do meet stringent burst pressure tests and cleanliness specifications, according to the automec website. Additionally, my friend Terry Jones, who also lives in Ontario Canada, fitted cupro nickel brake lines to his MGA 1600 roadster, which passed it's safety inspection with flying colours! Terry drove his MGA all last summer, and I can assure you that his brakes are top notch, and have withstood numerous panic stop tests, where considerable pressure was intentionally, and relentlessly applied to the brake pedal! I will certainly have no qualms about installing the automec copper nickel lines on my MGA 1500! hope this helps! GLenn
Glenn

The threads on the early unions won't ne Whitworth, far too coarse a thread. They are most likely BSF.
Malcolm Asquith

It smy understanding that Saab imports cars to Canada and they use Cupro-Nickel lines. How do they get away with it?

Jeff Schlemmer

Boy,
Now I am even more confused.Glenn,are you trying to tell me that the steel brake lines ,bought over the counter at an autoparts store are "technically unsafe" and yet the inspectors allow and even insist that they be used. The kit I have is from Automec and I even have the brochure that states all of the necessary DOT specs.One thing for sure is that the cop/nik lines definately look like copper colour unless they are "camoflagued" somehow. When I first heard of this problem I did spray paint one of the lines with flat grey ,heat resistant stove paint. The results were actaully very good and they look like the dark grey lines you can by OTC
I also read on the internet at www.fedhillusa.com that cop/nik is used on Aston Martins, Saabs Audi & Porsche. If these top of the line cars can use them why can't mine.
My biggest worry is taht I keep the cop/nik on the car ....load it full of fluid and then be told that they have to be changed.

So lts take a vote. all in favour of cop/nik say "yeh" all against say "ney".
Jeff, I am going to talk to the Saab ,Audi dealer and see if I can get some info to help me if I keep the cop/nik.

PS: I still have not found out what EW on the way means? Thanks Gord.
Gordon Harrison

As I said in my earlier post, the high end manufacturers that use this material submit an entire car for testing and acceptance, not a list of materials, and no one knows the specifications for the materials they use. Yes, I would favour cupro nickel, particularly after having two steel line failures in a VW in recent years.
John

Hi Gordon. Here in Ontario, Canada, metal brake lines sold at auto supply places are steel, with a thin galvanized coating. Since the lines are steel, over time they rust out. Since most brake fluid absorbs moisture from the air, it is not uncommon for the brake lines to rust from the inside out. One pinhole in a steel line will pump out all of the MGA brake system brake fluid with just a few pumps of the brake pedal, leaving the driver with NO BRAKES! This happened to me years ago with an old MGB, and I was fortunate that no one was killed or injured when my hydraulics failed. The Automec brake lines are NOT copper. They are a copper nickel alloy. The ones I purchased are the colour of shiny stainless steel, not copper. The automec brake lines cannot rust due to the copper nickel alloy used. These brake lines are strong and will not burst even under high pressure. Since they cannot rust, the worry of leaking steel hydraulic lines is eliminated. I put steel brake lines on my MGA back in 1980, because nothing better was readily available. Since my brake lines have not been changed since 1980, (but carefully inspected every year) and since steel lines can rust, I will be replacing them with the copper nickel brake lines this summer. For me the automec brake lines will provide a peace of mind that the steel lines never allowed. Personally, I think that regular steel brake lines should be entirely banned from use, since over time they can and do rust out, often with disasterous consequences! Cheers! GLenn
Glenn

Final decision has been made. I contacted the inspection centers that we use here in Quebec and this is the answer. COPPER is forbidden...no exception. Stainless steel is highly recommended....steel is recommended and copper/nickel is recommended. The key point to any inspection is the quality, condition and safety of the rebuild. All quality work will improve your chances of passing inspection. A well laid out ,non leaking , clean secure brake system will pass every time. So I have decided that "STEEL" will be the brake system for my car. It is available every where , fairly easy to work with, the car is not going to be winter driven and with proper maintenance the system will last for ever. Combined with silicone brake fuild and all new M/C and brake cylinders I am sure it will pass. Thanks to all. Gord
Gordon Harrison

Hi Gordon. I respect your opinion and decision to use steel brake lines, and if that is your final decision, so be it. However, since both steel and copper nickel brake lines are apparently "recommended" by the Quebec Ministry of Transport, I find it curious that you would choose inferior steel brake lines that WILL eventually rust, as opposed to the copper nickel ones that will not. I guess I feel the need to say that personally, I think that you are making a mistake by installing the steel lines. Having said that, I now feel better, and will shut up in regard to the topic. Cheers, and best of luck! Glenn
Glenn

If you follow the links in the Fedhill site, you will come across information from Sweden on why the CU/NI lines are superior to anything else, including stainless, which is prone to crevice corrosion in the fittings. I used to get bulk steel line from a BMC/BL dealer, very nice and very heavily terne coated (lead/tin) - lasted for years and was extremely easy to flare and bend. In the years since, I've found that each sucessive purchase from different sources has given steadily worse results, descending from terne coated, to heavy galvanized, to epoxy coated, to really crappy thin galvanized. I had gotten some good heavy galvanized stuff from JCWhitney, but the latest batch appeared to be the same as the ready-made autoparts ones. The latest lines from the normal autoparts stores give up in less than 2 years in regular use - I replaced a line on my truck in December, and it had rusted out in 14 months. Plus, they are more difficult to flare and are more prone to kinking than in years past.
FRM
FR Millmore

Hi Gordon. I lied. forgive me.

Abstract

For many years the tubing in automotive brake systems has been manufactured from low-carbon steel. One or more superficial coatings are applied after brazing to protect the steel substrate from corrosion, because steel has no inherent corrosion resistance to the road environment. Although coating composition has changed since the original hot-dip lead-tin coatings were used, coating flaws remain a problem. The addition of zinc-rich paints did little to improve the protection of the tube. Current aluminum-zinc coatings and added polyvinylfloride coatings are still inadequate to totally protect the steel tube.

In a recent series of tests, 90-10 copper-nickel tube (UNS C70600) was fabricated into typical brake system '.shapes" which were then attached to a test trailer and conveyed through various corrosive and mechanically abusive test track environments. The tests included holding the tubes in a high humidity chamber for a portion of each 24-hour test cycle. After 40 cycles and at each 10 cycles thereafter, the individual tubes were required to pass a 20,684 kPa (3,000 psi) pressure test. Candidate tube materials had to complete 60 cycles to satisfy the minimum requirement.

Current production steel tubes passed the 60-cycle requirement but failed well before 120 cycles. The 90-10 copper-nickel tubes completed 200 cycles with essentially no reduction of their original burst strength.

Figure 1.Copper-nickel brake lines running from master cylinder in 1990 Volvo.
Introduction

Brake tubes are located in a high-corrosion area. Although many other automotive components operate in the same hostile environment, few are less forgiving in the event of a failure. Thus, one of the major considerations in the design of an automotive hydraulic brake system is the integrity of the brake tubing which distributes the system pressure.

In 1965, an annual safety inspection of motor vehicles was introduced in Sweden and subsequently in other European countries. This procedure included the inspection of hydraulic brake tubes for the presence of rust. Concurrently, the Swedish Motor Vehicle Inspection Company began publishing annual reports on the results of these tests. 1

In 1969, laboratory tests were reported comparing some inherently corrosion-resistant copper alloy tube materials with the then-current production materials. 2

Early in 1970, the Swedish Corrosion Institute approached the brake tube corrosion problem from the standpoint of using a corrosion-resistant material rather than trying to protect the surface. 1

The European auto industry's initial response to brake tube corrosion problems was to terminate the use of the then-current hot-dipped terne metal coating over steel tube. Laboratory testing in a 6% neutral vapor salt spray test indicated that corrosion resistance could be obtained by a 25-micron zinc coating in place of the terne coating. In the years that followed, it became apparent that the laboratory testing had not accurately reflected conditions that exist in the actual operating environment. Subsequently, various plastic coatings were applied over the zinc and some are still being used to this date. 1

Efforts to achieve a metallurgical solution to the corrosion problem continued. Volvo began the use of 90-10 copper-nickel ("Cunifer Alloy") tube in their 1976 model vehicles and have been using it since. Figure 1 shows the installation at the master cylinder in a 1990 model Volvo. Audi began using this material in 1990. The other European cars using this material are Porsche and Aston Martin.2

Figure 2. Annual Swedish Vehicles Safety Inspection Results. The bars indiacate the percentage of 8-year old Vovlo passenger cars inspected in the indicated year with brake lines which did not meet the inspection requirements. 1976 was the year Volvo introduced 90-10 copper-nickel tubes ('Cunifer Alloy') into their vehicles.


The bar graph shown in Figure 2 depicts the percentage of vehicles failing safety inspections because of defects in the brake systems of eight-year-old Volvo passenger cars. The 1970 model cars had terne-coated steel tubes. Tubes in the 1971 models were zinc coated. Defects other than rusted tubes are included in these values, but their effect on the data is minimal. The reduction in defects related to the introduction of 90-10 copper-nickel tube in 1976 is dramatic.

The paper2 presented at the SAE Annual Meeting in January 1970 dealt with the then "state of the art" in tube coatings; the data presented in that paper are still pertinent. Voids, poor adhesion, discontinuities and physical damage to the superficial coatings used today can result in accelerated, localized corrosive attack which renders useless the value of any intact coating elsewhere on the tube.

An incident reflecting the latter condition was recorded in an SAE paper presented in 1991.3 A brake line which should have burst when tested at 1 1 5,832 to 158,579 kPa (1 6,800 - 23,000 psi), in fact, burst at 4,825 kPa (700 psi). The paper states, "This particular tube portion was located at the end, above and behind the rear axle, and showed a great deal of corrosion, perhaps due to gravel impingement."

Against the background summarized above, a test program was undertaken by the Copper Development Association Inc., with the cooperation of an automotive vehicle manufacturer, to evaluate thoroughly the applicability of Copper Alloy C70600 tube, 90-10 copper-nickel, for automotive brake line application. The tube material is described in Table 1.

Trailer Corrosion Test

The design test procedure generally used today to evaluate the corrosion resistance and integrity of motor vehicle body and chassis
Figure 3. Brake line samples attached to test trailer.

Figure 4. Equipment used to test hydrostatic pressure in brake tube.
components consists of 100 cycles of controlled humidity soaking and drying, salt spraying and mileage accumulation over various road surfaces with test samples mounted on a trailer. The sequence of test cycle events is listed in Table 2.

The trailer is exposed to salt, dust and stone pecking as well as temperature and humidity variations. The total humidity soak time is approximately 2,600 +/-25 hours. The total drying chamber soak time is 375 +/-25 hours. The test trailer accumulates approximately 13,800 km (8,600 miles) during the full test cycle. Total test time is approximately 26 weeks. Figure 3 shows test samples attached to a typical test trailer.

The tube size used for the test was 4.76 mm (0.1875 in.) outside diameter, 0.7 mm (0.028 in.) wall thickness. It was fabricated into typical brake system configurations with flares and tube nuts. The ends were encapsulated to allow subsequent pressure testing. These test specimens were then attached to various areas of the test trailer to assure exposure to all test elements at various degrees of intensity.

Beginning with the 40th cycle, and at 1 0-cycle intervals thereafter, each tube is subjected to an internal pressure test of 20,684 kPa (3000 psi). Candidate materials must complete 60 cycles to satisfy the minimum requirement. Figure 4 shows the test equipment on which the hydrostatic pressure tests were made.

This performance would be expected even if a measured superficial abrasion had been inflicted on the tube as a condition for the evaluation of the tube surface.

Test Results

The data in Table 34 reveal that after 200 test cycles, which exceeds three times the minimum benchmark of 60 cycles, the copper-nickel material retained more than 89% of its initial average burst strength.

Also noteworthy is the narrow spread in post-test burst pressure. This attests to the uniformity of copper-nickel's strength and physical properties, a feature which is not present in the currently used coated carbon steel tube.

Additional Testing
Figure 5. Engine compartment of 1976 Volvo showing uncorroded copper-nickel brake lines.

Figure 5 shows the engine compartment of a 1976 model Volvo four-door sedan. The vehicle was located in the storage yard of a used automobile parts dealer. The engine had already been removed and the actual mileage is not known. However, using the corrosion in the engine compartment as a criterion, it can be concluded that the uncorroded copper-nickel brake tubes which can be seen exiting from the master cylinder had, indeed, survived a hostile, corrosive environment.

The brake tubes were removed from this vehicle and hydrostatic burst tested with the following results:
Tube No. 1 111,694.95 kPa (1 6,200 psi)
Tube No. 2 106,868.62 kPa (1 5,500 psi)
These real-world data are welcome confirmation of the trailer test results.

Summary and Conclusions

The automobile industry faces many challenges in the market place and on its test tracks. It must produce vehicles that will compete in a world market on the basis of quality, safety, reliability, durability and cost. The test results presented above demonstrate that 90-10 coppernickel tube is a significantly better choice for automotive brake lines than low-carbon steel because:

1. The use of an inherently corrosion resistant material is the best protection against long-term brake tube corrosion. This has been demonstrated by Volvo, which uses 90-10 copper-nickel tube in automobiles they have produced during the last 15 years.
2. The results of trailer corrosion testing indicate that 90-10 copper-nickel tube (UNS 70600) is a superior product compared to the coated steel tube used for brake lines in today's U.S.-made vehicles.
3. Current double-wrapped, brazed and coated steel tubing is susceptible to brazing voids, coating voids, poor coating adhesion and discontinuities. These susceptibilities, combined with random service damage, mean the actual service life of the brake tube materials presently used in U.S.-manufactured vehicles should be considered unacceptable.

It must be recognized that all underbody components, including the brake tubes, will be struck by objects thrown up by the tires. Such random damage must be considered the most vulnerable link in the chain.

The tubing designer generally specifies the addition of a metal or plastic sleeve to the tube areas believed to be most vulnerable to stone damage. However, an inherently corrosion-resistant copper-nickel tube provides the surest protection against such random service damage, especially compared to a coated steel tube.

References:
1 Svenson, G.E., Swedish Motor Vehicle Inspection Company, Brake Pipe Corrosion the Situation 1986, Except from ISO Document 150/22/2WG 8N 82, February, 1986.
2 Ingram, A.G. and Miner, D.K., Hydraulic Brake Line Corrosion; An Initial Investigation of the Problem, SAE Technical Paper 690530; presented at the SAE Annual Meeting, Detroit, Michican, May 1969.
3 Bologna, D.J., Accelerated Corrosion Tests and the Evaluation of New Automotive Brake Line Coatings, SAE Technical Paper 912292, Conference, Dearborn, Michigan, October 1991.
4 Brantigan, J., Control Power Company, Hydrostatic Burst Test Results, September 11, 1992.

Glenn

Geeze Glenn
I hope you did not type that all by hand.LOL.As for my Automec kit I am confused because the box they came in specifically states right on the front COPPER BRAKE LINES and does not suggest anything else. I questioned this with Automec and they sent me a reply stating and I quote "WE USE ONLY USE THICK WALLED (.9MM 20s.w.g) PURE COPPER PIPING,WHICH IS GENERALLY MARKED WITH OUR NAME EVERY 4" TO DISTINGUISH IT FROM OTHER PIPING WITH A WALL THICKNESS OF (.7mm). And here is the important part, "WE CAN ALSO MAKE PIPES IN COPPER-NICKLE,IF PREFERRED".
This tells me that what I have is pure copper and is not acceptable and is not even safe according to other people.
Am I doing the right thing by using steel.....I don't know...and this worries me. How do I convince the inspection people that copper-nickle brakes lines are safe. Glenn remember this is the QUEBEC GOUVERMENT.

So I am going to try and find copper-nickle brake lines and take my chances at the inspection center. Remember the most important cread of the MG is


SAFETY FAST
Gordon Harrison


WHAT DOES .....EW....MEAM !

I have the answer. My search for the definition of the lettering EW on the 3way brake union at the rear axle of my car comes from....and get this ,a cheap plug for CHRISTIAN HOLLUM IMPORT (origional british Parts) Lachine Quebec 514-639-4639.

It seems that these 3way units were origionally from a 1948 & up Morris Minor. They were manufactured by a british company called Ewett. Therefore the EW marked on the unit. These units were used on MGA'S up until app #47000 and then they were all changed to UNF thread. These units have a distitive collar around the upper extention,where the rubber brake line attaches.This collar was ground off when the change was made to UNF all around to distinguish them from the earlier ones.
Gordon Harrison

Boy, am I glad my daily driver is a 92 Volvo 740!!
Art

Hi again Gordon. No, I did not type the last thread out by hand. Copy and paste only! lol. As for your copper pipes, they might be pure copper, in which case they would be illegal not only in Quebec, but likely across all of Canada. The automec brake pipes that I purchased through Moss motors come in a green box, with yellow automec logo. The box is labelled "Copper brake pipe set" but overtop of that statement is a stick on tag that says "NB This set is top quality Copper-Nickel brake pipe- Not pure copper." The Automec copper nickel brake lines I have are NOT made of pure copper, and are NOT copper coloured. The lines are a silvery colour with perhaps just the smallest hint of copper colour mixed in. The numerical codes on my Automec brake line box are: GL5025, and 183-088 and GAC5025L. d The lines were ordered for an MGA 1600 roadster. My car is actually a 1500 roadster that was converted over to front disc brakes. Gordon, if there is any doubt as to whether or not your lines are truly copper nickel alloy, than I would not use them. Pure copper lines would be illegal and unsuitable for use. If you are uncertain, I would contact automec directly and ask them whether your particular pipes are pure copper, or copper nickel. Again, I personally would not put steel lines on your car, since they will eventually rust, no matter how carefully you install and maintain them. I would go the distance and install the Copper nickel brake lines, since they will never rust. Since your Quebec Ministry of transport says copper nickel brake lines are acceptable, I dont think you would have a problem during the safety inspection. Copper lines are copper coloured, copper nickel lines are not copper coloured. You could bring the box that the copper nickel brake lines were shipped in, as proof that copper nickel lines were actually installed. But frankly, I dont think the inspector would even notice the difference between steel brake lines, and the copper nickel ones. Again, best of luck with the brake line situation. Cheers! GLenn
Glenn

Hi again Gordon. THe Automec copper nickel brake lines have data stamped on the outsides. My brake pipes read as follows: 3420 and 4.76MM X 0.71 MM and 3/16X 22 G and CN102 ECT BS EN 12449 and Made in the E.U.
Hope this helps to identify what pipes you have. Glenn
Glenn

Glenn,
That confirms it. My Automec lines .....look like copper......smell like copper.....take like copper...so they must be copper.
Thanks to everyone for their help. It will be copper-niclel ,if I can find them locally or steel against the wishes of Glenn but for now this thread has been beat to death and is CLOSED. Thanks All
Gordon Harrison

Let me try to throw a bit of light on this. Automec still sells pure copper brake lines in the UK market. These as Gordon states, look like copper, smell like copper and take (sp) like copper.

They are not DOT approved for the US market.

For the US (and Canadian) market they produce a line of Cupro-Nickel lines that have a light gold colour and meet DOT and (evidently from Gordon's statement) Canadian requirements.

The Automec line kits sold in the US should only be Cupro-Nickel, but that does not stop smaller suppliers from buying and importing non-legal UK kits.

Hope this helps.

Kelvin Dodd
KJ Dodd

Kevin
You are absolutely right and I did buy them from a USA company that regularly attends the British Invasion (selling out of a new big aluminum trailer) at Stowe Vermont. They sold them to me without the least "hint " that they were not legal. As they say"Buyer Beware"
Gordon Harrison

Hi Gordon. I wonder if you could send them back to automec for an exchange for copper nickel lines? Glenn
Glenn

Gordon:

The supplier very likely did not know that the lines were not DOT or Canadian approved. These lines were generally available for quite a while before the legal implications became known.

kelvin.
KJ Dodd

Sorry to prolong this thread, but what is wrong with copper? If it's OK in the UK why not over 'ere?
Art

Hi Art. My understanding is that copper is metalurgically brittle. Because it is brittle it can fail under high pressure. Cheers! Glenn
Glenn

So, it's not brittle in the UK?
Art

""""tongue in cheek mode!!!""""

"thousands of Brits dying everyday with failed copper brake pipes!!""

You will be pleased to know ART we are not dying everyday and in fact copper brake lines are far safer than steel due to steel lines rusting out in just a few years!

My midget has had copper lines fitted on it for 20 years. No signs of it becoming brittle or splitting.
Bob (robert) I am coming out!! yes I once owned an MGB!!

Hi Art and Bob. Im not a metallurgist or a hydraulic expert, but I do personally feel that copper brake pipes have probably been given a bum rap. I have heard numerous people over the years state that they have used copper brake lines for many years, without failure or incident. However, North American lawmakers have "determined" that copper brake lines are unsafe. My understanding (according to the "experts") is that copper brake lines are inherently brittle and become more dangerous as they expand and contract (imperceptably) under pressure, subsequently "work hardening" in use. Supposedly this work hardening weakens an already brittle tube, which can then fail at any time. Having personally had a steel brake line fail (from rustout) many years ago, on my single brake hydraulic system MGB at speed, I can understand why brake tubing safety is such an important issue! (Believe me, there is no panic quite like stepping on the brake pedal at road speeds,in a high traffic area, and finding that you have NO BRAKES!!!) Unfortunately, I dont believe that steel brake lines are safe in any way shape or form, since they can rust away in an unbelievably short period of time. Further, steel brake lines can rust away from the outside in, or the inside out. In Canada, where copious quantities of salt is used for ice removal, this means that steel brake lines are HIGHLY susceptible to rust damage! Most cars on the road in Canada are driving time bombs, just waiting for brake failures to occurfrom rust damaged brake lines! Most North American drivers know little or nothing about the vehicles they drive, and have no idea that brake lines can rust out with catastropic results. Consequently, brake lines are seldom inspected or replaced, unless a sharp eyed mechanic happens to notice a problem during routine maintenence! Although all modern cars have dual hydraulic brake systems, a failure of any one steel brake line still means there will be braking on only 2 of 4 wheels. In a high speed panic braking situation, this means that there IS going to be a collision! Personally, I believe that steel brake lines should be entirely banned form use on a global basis. Again, personally, given the dismal track record of steel brak lines, I would take my chances with pure copper brake lines, over the steel ones any day! Given that copper nickel brake lines are readily available, and never rust out, one has to wonder about the sanity of automotive "safety experts" that continue to advocate the use of steel brake lines which are by their metallurical nature, prone to rust failure, and therefore being unsafe. Sorry for the rant! Glenn
Glenn

Bob and Glenn, just teasing. I too think copper should be just fine. It does not corrode (unless you spray it with ammonia or nitric acid) and has sufficient strength to withstand the miniscule stresses that result in small bore tubing. It is also soft or hard depending on heat treatment. Lots of good stuff gets banned these days for the slightest suggestion of a problem, by politicians / officials who want to cover their backsides. Why, even good old sawdust has recently been designated an environmental hazard in Ontario!
Art

This thread was discussed between 07/03/2006 and 12/03/2006

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