OK, after setting the job aside for a while, the cover is off and both lines are shot on both sides of the union. All that came out of the covered area was a handful of gravel and some dust. It wasn't packed with muck. Still both lines toast. Repair parts on the way.



Underside of the vehicle is otherwise clean(ish). Sure, there's a little surface rust on exposed parts, but up here we drive our cars regardless of the conditions. I'm not about to go crawling around under my car in -30C to get some dirt and salt off it.



Also bear in mind that we're talking about a 15yo car that might be worth C$4000 on a good day. 30 years ago, a car this old would be too rusty to even drive. This one (and our other X5, and the '08 535xi) don't have any rust spots anywhere on the bodywork. We even (gasp!!) park them in a heated garage every day, all winter, which is supposedly the worst thing you can do for rust.


So I've got that going for me. Which is nice...

Cinderella story... Coming out of nowhere.

... now about to become the Masters champion. [swings, pulverizes yet another flower] It looks like a mirac- it's in the hole! It's in the hole!

had all of our rear hard lines done a few years ago for $400 which was a pretty good rate now looking back on it...

That is killer. Dealer quotes are like $1200-1400


Sent from my iPhone using Tapatalk Pro

Couple comments:

1. The photo posted above by audiophool is interesting: only 2 out of 5 metal lines are rusted.
The other 3 lines seem OK. Reason?

2. Salt + heat (whether heated garage or 30C day in July-August) accelerates the corrosion process.
I am not advocating doing anything when it is -30C.
What I am saying is: any day above 2-3C, drive to a car wash place (I go to the $3 self-serve place so I can spray the water the way I want), do a quick clean of the body. Then rinse not only the body but also the chassis.
All I do is get a cardboard and kneel down to aim the water 45 degrees UPWARD under the chassis from the outside. Trust me, a bit water here and there on days > 2-3C helps a lot.
In fact, if you do this water wash religiously, you won't have any rust.

3. For the rear lines near the caliper as shown previously, go behind the car and aim water just BETWEEN the Rear Shock and the Rear Tire, water will get to theses metal lines.

Real easy answer. Two that are rusted are the brake lines where the cheap material used for a coating failed due to the bending by the supplier prior to assembly. Cheap materials, cheap coating = part failure. The other lines are a plastic/ polymer material not steel.
The brake lines will all fail in time. Those who live in a low humid temp area of the world will NOT see the end life as no rust develops on the exposed tubes.

For everyone one else it is When not IF. This failure is very common across whole segments of the auto world. You can even see complete brake line kits from aftermarket suppliers. Nope no BMW kits available yet just the braided lines from calipers to the frame points.

Examples
https://video.search.yahoo.com/searc...e&action=click

https://agscompany.com/ez-fit-chevy-brake-line-kit/

Wash the chassis on warm days during the winter.

But that assumes you do that since new. When you inherit the cat from P.O.s, you don't know how it was cared for but you can still wash the chassis to limit the damage.

The weakest point is shielded from any useful rinsing or observation. You can. Get in a couple times a year by removing the screws on the inboard side and bend the plastic down.

Nah, now these are fixed they'll surely outlast the rest of the car. Gave them a good blast of Krown before buttoning it up, just for good measure.



And since the 535 is about to go under the knife for new shocks (Bilstein B6 all around), it'll get a full inspection and whatever needs addressing will be done.