How many times have we heard this: "why do I need to replace my brake lines, they look fine?" Why indeed. FIRST REASON: YAMAHA said they were only supposed to last FOUR YEARS. Four. Not thirty. Check your date codes. Sometimes they're easy to see: Sometimes you really have to look (this one says 5/82) EVEN MORE IMPORTANT REASON: I "sectioned" a couple of old lines (12/80 and 5/82) to see exactly what we're dealing with. There is an outer rubber sheath, then a layer of metallic-appearing (but it's NOT) woven cloth (nylon?) then the red rubber outer-inner hose, with a woven layer fused between it and the black inner liner. That part won't peel apart, it's bonded/molded together. NOW LET'S EXAMINE THEM MORE CLOSELY. See pic below. Note that in the hose on the left, you can see the inner black hose cracking and crumbling away. It's even more frightening under a magnifying glass, I think the Canon got a good look though. Note that in the hose on the right, there is a readily visible SPLIT in the inner hose. CRACKING, CRUMBLING AND SPLITTING OF THE INNER HOSE: DOES ANYBODY NEED ANY MORE CONVINCING? I got more old brake hoses I can cut up... Besides, stainless lines are sexy... C'mon, people. Just because you can't readily SEE the problem, it's there. Replace your hoses. You can get original-type hoses if you don't want to upgrade to stainless; but replace your old hoses. With NEW ones.