Originally Posted by
FlashBazbo
I have ridden hydraulic disc brakes for five years and have two or more years on four bikes equipped with them. Over 100,000 miles. I bled the brakes meticulously (obsessively) when I installed them. I have never, ever had to re-bleed or replace the fluid on any Shimano hydraulic disc brake. They work exactly the same years later as they do on the day I install them.
If the initial installation is done meticulously (obsessively), there's no reason to have to maintain anything other than pads and discs as they wear out. If it was installed well, keep the hydraulic system sealed and it will be your friend for a very long time.
...and there you go. It's because it's Shimano.
Still.... Brake bleeding hydraulic is not a rare phenomenon regardless of how well you set it up. Well designed systems that are set up correctly will usually be fine for a long time if someone is regularly riding them and generally treats their stuff well. Just like with flat tires, blown out bearings, etc you can get riders who just quite simply treat their gear like crap and don't realize it.