Hi all,
I posted a response the other day, but it seems to have disappeared.
I have to strongly disagree with some of the other responses to your questions.
Greg, please look closely at the fittings on your TR3 when you disassmble the brake lines. I think you will find there are *two* types of pipe end shapes used on your car. If so and you were to use double flares throughout, it's possible some of them will leak and that might lead to brake failure.
You should find these two types of pipe ends:
One is the standard double flare. This is pretty easily made with any brake line flaring tool, with a little practice and care. Just as the name implies, it's a two-step process to make this flare on the end of the pipe. It's well illustrated in the instructions that come with the tool, I'm sure. This type fitting is used on our older TRs (I dunno about the newer ones) anywhere the fitting on the end of the pipe is "female" and what it attaches to is "male". Examples are the upper end of the flex hose coming off the clutch slave cylinder, or the front caliper flex hoses where they attach to the brake pipes.
The other type of end you will find on the pipes is often called a "British bubble". This is used wherever the fitting on the end of the pipe is "male" and what it attaches to is "female". Examples are all the fittings at the five-way connector down on the RH front frame rail of your car. Also both master cylinders on my TR4 use this type. (But, I don't know for sure if TR3 MCs are the same, they are quite different from TR4.) This is not a single flare, per se, but the "British bubble" can also be formed with the standard flaring tool. It's actually faster and easier because you just skip the second step (done for the double flare) and only do the first step. What you end up with is a small "bubble" on the end of the pipe.
I see that both types of ends and how they are formed are shown at the link above, that Mike provided in his post.
Note: There is also a special tool for making "British bubble" pipe end fittings. However, I've never had any trouble forming one with the standard, cheapo tool found at most auto parts stores.
How easy this whole job is depends to some degree upon the material of the brake lines you buy.
The popular "Kunifer" or copper/nickel type found in many of the kits is the easiest to form. It's also more easily dented or damaged, actually is not U.S. DOT approved for new car manufacturers in the U.S., but is in wide use throughout the world by many major car makers so I wouldn't have any concerns about using it.
OEM style steel with some sort of protective coating are a bit harder to work with, but still can be formed with the standard tool (it will wear out rather quickly). This is standard OEM on cars built in the U.S., meets DOT standards, but is the stuff that rusts and corrodes eventually. These types of lines are the most widely available and are cheap.
Forget about making up stainless steel lines yourself unless you want to invest in some very expensive, hydraulically-assisted and specially hardened tools. S/S is tough stuff and is usually best just bought pre-formed and ready to install.
P.S. You can also identify which type or pipe end to form by looking closely at the fitting where it will be seated. If you see a cone shape protruding towards you in there, it uses the double flare. If, however, it is concave such as might be done at the bottom of a drilling, then the bubble type end is used.