I'm glad you posted this. I too was thinking about braided lines. Get this, when I had some maintenance done at a local dealer I asked the service guy about adding SS lines to improve braking. He said the lines inside the rubber are SS. He was a nice, so I took him for his word. After thinking about it some more...yeah, I feel foolish and wonder if he really knew what he was talking about or just seeing if I did
Any noticeable improvement with regular driving?
I cut some high pressure lines in the past and noticed some have mesh that is like a plastic or teflon, some have fabric. Some have a steel mesh. All of them do have some sort of mesh because rubber itself is too flexible and will burst without the mesh. So I wouldnt say the guy at the dealer flat out lied to you. Would be interesting to take the old Tacoma lines and cut them apart to see how they are actually designed and with what.
On my MR2 I upgraded the lines to SS, as well as better pads and fluid. On a stock vehicle the pads and fluid are the first that need to be changed if you have braking issues. The pads fade with heat as they are designed to work within a certain heat range. Those that are designed for racing (constant braking) or for braking power coming down the mountain ranges are not going to work as good as stock pads during normal daily driving because they are not going to build up enough heat to operate in their ideal temperature range.
Brake fluid is also designed to work within a heat range. So if you exceed that range, much like engine oil, the fluid breaks down. If broken down it needs to be flushed out and replaced with new fluid.
The aftermarket SS brake lines are just higher quality brake lines that will retain the higher pressures without expanding as much as the OEM quality lines. Obviously I never cut any of the SS lines I purchased because it would be destroying them, but Id imagine they may have 2 layers of mesh. I definitely noticed they are thinner then the OEM lines were. The SS mesh on the outside I believe helps dissipate heat build up as well.
The big drawback to SS lines is some of them are not rated for street use. This means that they are not rated for quality or dependibility, which doesnt really matter too much for racing purposes because its a controlled environment and the systems are constantly being checked.