Rusted brake lines, anyone?

[amacman]

Thanks for clarification JCL.
as far as I know the copper alloy is the only stuff available in brake pipe sizes but it is best to ensure using the correct pipe .

[DetroitMatt]

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.

[TiAgX5]

Salt corrosion is the main reason I will never buy a vehicle that has been operated in the "rust belt". The road dept spreads salt and other crap on icy roads and when you drive over it your tires turn it into a saltwater (corrosive) mist that gets EVERYWHERE. The best bet to avoid this is to drive 2ndary roads that are not salted (used to do this when I lived in the northeast). Remove the covers every spring before a detailed chassis flush/wash followed with a light lube chassis spraydown after dry is a must for everyone in the yellow area of the map below.

My '03 X is in the 10th yr of service and other then a light coating of dust/dirt those lines look new, but my X has never seen snow/ice.

[DetroitMatt]

I agree that it's the salt that's causing the issue here, and probably why both of my cars suffered from the same issue at nearly the same time.

I also just did some more research and it turns out that you apparently do have to basically drop the entire rear end of the car to get the new lines in. Hopefully someone here might have a way to get around that. Otherwise this looks like a HUGE repair.

[romeokc10]

But you would think BMW would know better, being an airline pilot and in the Air Force I've spent many a winter night in Germany, the winters are brutal there!

[SlickGT1]

You splicing them should be fine as long as you used the proper lines. Leave it that way. Coat the lines with POR15 if you are in the rust belt. That is the sauce.

Brake fluid leak at an individual location will not render you brake less. You have a bunch of time till you lose enough fluid to empty out the reservoir. I know this because a drilled rotor blew up on me once destroying most everything attached to and including my wheel. No brakes. Bent the line, squished it, and drove home with it dripping. So keep it cool with those rusted lines, just don't leave them that way. Address the issue.

[sedc]

This is a very common problem in that exact location on E53s.

Solution is to splice in new brake line, no need to re-run the entire lines.

[flatlander]

Does anyone know the splice tubing size to use for the X5?

[amacman]

4.75 mm pipe or nearest equivalent .

[TechWrench]

Just remember, that if you decide to repair the lines by splicing in a section to replace the damaged one, they are high pressure lines. Don't use standard compression fittings. You should only use flare type fittings, with double flares on all ends.