Eldo 95 ETC in need of new metal brake lines

Henrik · #1 (**permalink**) 10-11-06, 11:12 AM

I imported my low miles Cadillac Eldorado 1995 ETC to Europe and am now in the process of upgrading lights, sidemarkers, blinkers etc. to adhere to local rules. I probably need to replace a large part or all of the metal brake lines to pass inspection here due to corrosion showing (no leaks). I will use copper lines, as I have done sucessfully in the past for my old Mercedes. Did any of you perform a similar operation? How many hours should the local Cadillac dealer be able to do the job in? Thanks for any pointers or answers.

best regards, henrik

100 · #2 (**permalink**) 10-13-06, 01:29 AM

I believe GM specifically stated not to use copper tubing for brake systems. It does not hold the pressure. I believe it is somewhat related to the use of ABS system. Well, I don't remember where I got this...

I replaced some portion of the brake lines with steel lines (made for brake lines). It is much more difficult to work with. It was a time-consuming work, I think it would take a few hours for a dealer technician.

Good luck.

Henrik · #3 (**permalink**) 10-13-06, 07:22 AM

Thanks 100, This is a Cadillac dealership over in Denmark that will do the job. I have very good experience with copper lines which is what everybody will do around here on any car that needs the job done. It is easier to work with, it corrodes far less and it will work also with the pressure of an ABS system. I actually met another gentlemen at the dealer who had a 94 Eldo who had the same operation performed a while back and it worked just fine. The dealer tell me that it is major operation to replace all the lines. I was under the car and I believe them, all the lines looked very corroded to me. So this is going to set me back quite a bit before we are done. Thanks again for your comments.

EcSTSatic · #4 (**permalink**) 10-13-06, 03:39 PM

Google on "copper brake lines" and read all of the posts saying never to use copper. As mentioned, the bursting strength is inadequate.

Henrik · #5 (**permalink**) 10-13-06, 04:21 PM

I respectfully disagree. I have always used copper brake lines (made specifically for brake systems). I have never experienced nor heard of any one else in my country that had a bursted copper brake line. I have however heard of others that had failures with corroded steel lines. I have had many cars throughout my life, and many were old and worn and most had copper lines. Never a problem. All cars have ABS today so this should apply to all cars. As mentioned, I am sceptical. Also notice that our vehicle inspection (which is MUCH more thorough than the one I saw in US accepts copper lines). If I am not mistaken the same is true in Germany and Sweden as well.

HUF · #6 (**permalink**) 10-13-06, 04:29 PM

Quote:

Originally Posted by EcSTSatic

Google on "copper brake lines" and read all of the posts saying never to use copper. As mentioned, the bursting strength is inadequate.

Probably they have thicker walls. The inspection in Europe is much tougher, that's for sure.

Henrik · #7 (**permalink**) 10-13-06, 04:31 PM

OK, so I followed your advise and did some research on the internet. I did find an article that stated copper lines did not belong on a race car but were ok on ordinary cars. I also came across the following (source: Applications: Automotive - Hydraulic Brake Tube)

Food for thought!

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.

100 · #8 (**permalink**) 10-13-06, 11:37 PM

If it works (and inspection says OK), I think it is OK. I could not flare the end of the tubes, so I put 2 brass compression fittings in my rear brake lines (supposed to be big no-no). I keep watching them and I have not had any troubles (yet).

Anyway, if you can get "automotive brake line copper tube" from a reputable manufacturer, I think it is OK to use. But... is it softer than steel tube (easier to work with then)? Probably the best idea is to use stainless steel tube...

BTW, this PDF contains pretty good info:
http://www.swagelok.com/downloads/we.../MS-01-107.PDF

The brake lines for my car (95 DeVille) is 3/16 inch OD and seems like conventional (not Ni alloy) copper tube will not be able take 3000 psi, unless you use the thickest wall one. Maybe aluminum tube is a good option, too, haha.

Zorb750 · #9 (**permalink**) 10-22-06, 05:59 AM

Copper is not acceptably with the ABS, Traction, and Stability systems on this car. The lines will see far too high a pressure far too often.

But don't listen to us. Maybe none of us know anything at all...other than the fact that you might just drive your car right into a telephone pole if you use copper.

Henrik · #10 (**permalink**) 10-23-06, 06:01 PM

I do listen to you, I just don't agree with all the points being brought forward in this discussion thread. And more importantly, neither does Volvo, Porsche and other leading car manufacturers, that fit their cars with copper lines. Volvo has always been a leader in delivering very secure cars for decades. And Porsche probably has the best brakes on any production car in the world today. Correctly fitted copper lines of the proper kind will not cause problems. I have lived both in the US and Europe and there appears to be a big difference in how this subject is being treated on each side the ocean, which is for example signified by the fact that the local Cadillac dealer here in Europe actually does the copper brake line install job for me. They also recommended me to get the job done using copper, it was not me who insisted on it. Most Cadillacs operate in the US, so I am sure I belong to a minority here. Being a minority does not mean that I am wrong though.

100 · #11 (**permalink**) 10-23-06, 11:56 PM

Henrik,

When you say copper tubing, is it really a copper tube? Or is it what you called 90-10 Cu-Ni alloy tube? I found a quite bit of information on 90-10 Cu-Ni alloy, but I would like to know if what you are going to get (at a dealership for brake lines!) is that or just a simple copper tube. Yeah, it was very hard to work with steel tubing and I know they will get rusted.

Thank you!

Henrik · #12 (**permalink**) 03-27-07, 05:13 AM

A quick update, almost half a year later. I fitted the copper lines, as indicated in my previous posts. Car still drives and brakes like a dream. Best Regards, Henrik.

Henrik · #13 (**permalink**) 03-28-07, 04:20 PM

100, I apologize I did not answer your question. Yes, I used copper-nickel alloy seamless brake tubing. I am not sure of the exact composition.

Best regards, Henrik

Henrik · #14 (**permalink**) 06-26-09, 06:52 PM

Hi Everyone, just for the record my car is still braking fine, my brake lines look fine and everything works to my satisfaction despite the fact that I did not install steel lines.

best regards Henrik