i have been in the automotive industry for over 38 years. some times, when i am in need of a product quickly, i find Amazon helpful, so i can take care of my customers needs. that said, lets look at a few misconceptions about brake lines. on most cars and trucks, DOT 3 fluid is required. DOT 3 is a mineral based fluid that can hand up to 2500 psi and close to 400 degree conditions. however, just like silicone based DOT 4 & 5 fluids, they all absorb water, which under heat and pressure, turns to a oxygen rich gas (air) and moisture. these will turn into air pockets, giving you a soft if not no pedal pressure at all. go outside and look at your master cylinder; i’ll wait. okay, the fluid color is brownish, correct? guess what? you have rust, from water being in your system. now, if water is left alone in a system, it will start to rust the tubes from the inside out; why? because you also have air inside. when you press the pedal, the fluid goes outward, into the lines and when the pedal is lifted, the fluid goes back into the cylinder, taking the water and air with it. multiply this action, thousand of times, and you can see, your fluid is brown and your system is full of rust. rule of thumb, which no one follows, including myself, is to flush your system at least 1-2 years. like with pads and shoes, now brake components have become “wear items”, meaning we have to periodically change them out. as well, your calipers and wheel cylinders are rusting and pitting as well. i get customers every day wanting to splice they lines and replace with the use of compression fitting. STOP! when you see rust on the outside of your line, you don’t see really where the rust is. that’s right, it’s festering inside the lines. no amount of compression is going to seal the lines together as they are falling apart from the inside. protect yourself, your family and those driving around you; if you have at failure, because you not repairing the system correctly, you are playing with death.without going any further about killing yourself, lets look at the lines being sold here. all brake lines, steel, or coated steel, are only as good as the repair that was done. there are some that complain these copper lines rust. .while they are a moly, the steel backbone is coated by copper. copper will tarnish, but will not rust. salt can and will corrode it, but rust, never. what people see as rust, is what already exists on the steel or iron components. please understand, a repair is only good as the rest of the components. replacing one line, is not fixing the root of the problem; REPAIR AND REPLACE. you have to do both. replacing is not fixing the issue at hand; you have a fully contaminated system full of rust. clean and reify the rest of the system is in good shape, then replace what is left.