I hate to revive an old thread, but I just had this happen to my 2003 X5 4.4i. And mine look much worse than this! I lost my brakes on a road trip, so I got some extra pipe and a flare tool and spliced in a reapir piece, but I'd like to fix both of those lines the right way with all new pipe. I found the part numbers on Real OEM, and I'm about to order them, but I'm a bit scared to install them. I see that they both go over the back axel and then disappear from sight. Has anyone every replaced these lines before? Is there a DIY somewhere? I searched but couldn't find one.

On a side note, this exact same thing happened to my 2004 E60 less than a month ago. Very frustrating. I've had cars much older than these two and neither has given me grief like this. With something as important as brakes, you would think they'd have a more robust coating on them. I drive my kids around in these cars, and losing brake pressure is a dangerous occurrence.

Anyway, I'll stop ranting and if anyone has any personal experience or DIYs they could share on the replacement on this 04 X5, I'd greatly appreciate it. I'm really nervous that I'll have to drop the gas tank or major rear suspension parts to get to it.