I have a 1965 122S with single circuit brakes - no vacuum booster. I will soon be doing a makeover on my brake hydraulics. I noticed that hard lines (sometimes called pipes) are available from VP Autoparts, and they are faily cheap (a whole set for about $56). But they are copper, wheras (I believe) the originals were an alloy of copper and nickle (the same alloy that a U.S. 5 cent piece is made out of).
Anyway, my question is, my original hard brake lines seem fine, I don't see any damage. And since copper/nickel alloy is just about corrosion free, I don't see any reason to replace them. If I had one that was dented or bent, that would be another story. I can't see replacing them with copper tubing, that will corrode over time. So am I correct? Or should I replace these lines that are now 40 years old?
Tom

"...wheras (I believe) the originals were an alloy of copper and nickle (the same alloy that a U.S. 5 cent piece is made out of)."

Tom,

I suggest a magnet test on your OE hard lines. I have a bunch of 140 lines that are definitely steel. To the best of my knowledge, the copper alloy lines began with the 240 (see quotes below -- sources forgotten). I doubt that Volvo would go from a copper alloy on 120, to steel on 140, then back to copper, but who knows? A magnet will tell you real quick.

I also doubt that those new replacements are plain copper, since the cupro-nickel has been around since the 70's.

Copper Alloy Brake Lines:
"...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."

"Users of copper-nickel brake tubing in addition to Volvo include world-class vehicle manufacturers like Rolls Royce, Lotus, Aston Martin, Porsche and, most recently, Audi. Copper-nickel is also used in military, fire fighting and other heavy vehicles."
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Thanks, I had no idea. I will test them with a magnet as soon as I get home today. If they are steel, I will definitly replace them. I will follow up here tomorrow with my results.

Just being steel doesn't mean they are holed. The labor and expense is up to you and your comfort level.
I say clean and inspect first.

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Mike!

I checked, and they are steel. I don't know where I got the idea they were something else. But they work fine. I am going to replace the hoses. I will see how the hard lines hold up after being disconnected from the hoses and cleaned. I will decide what to do then. Thanks for everybodys help.

I'm with you on this. The hard lines tend to either split or develop pin-holes at (obvious) rub-points. Anyplace there is a vertical bend (forming a "u"), at unions or where a hard line touches either the body or a clamp are all spots that corrosion tends to initiate.

Usually the fluid will "weep" out of a small pin-hole and you will notice an unusually rapid loss of fluid in the reservoir before the brakes give any indication of trouble at the pedal.

Bad flex-lines are another matter entirely!

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Mike!

I would base my judgement on the appearance of the brake fluid when you flush and bleed your brakes. That's about the only way to gauge the condition of the insides of your brake lines. If the fluid you flush out of the system has little bits of junk in it, those bits of junk are coming from the insides of either your master cylinder, wheel cylinders, or lines. You can open up the wheel cylinders and have a look inside farily easily, the master cylinder a bit less easily, but you can't really see the insides of the brake lines.

I agree that the original materials are probably tougher than new steel lines.

I do have little bits of crud in my system, but I suspect it is from the master cylinder which looks very old. I have a new one to put in, and I have new rubber hoses too, I was just contemplating if I should have to change the hard lines too. I was hoping to leave the calipers and wheel cylinders alone for now. The brake pads look like new, and I have no leaks.
I think what I will do is buy a bunch of brake fluid and after I put in the new master cylinder and hoses I will bleed the system at the hoses and if it looks ok, then I will connect the hoses and bleed everything again at the bleeder valves. If nothing else, all this bleeding should clean out the system pretty good.
Tom

Hi,

I'm doing the same job at the moment on my '67. I noticed that the long pipe that runs over the rear axle had developed a very slight weep at the highest point of the axle - it might be worth checking yours too as this pipe might be more prone to friction damage than the others. The other problem that I had is that the fitting at the end of each pipe had seized onto the pipe and was very difficult to release without twisting the pipe itself - makes it hard just to replace the flexi hoses.

The amount of sediment in my master cylinder was unbelieveable....

Aidan
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1967 131, 1969 131, 1973 Triumph GT6