DIY: 2006 BMW E53 X5 3.0i Brake Line Replacement

[2004bmwx53i]

Originally Posted by andrewwynn

The weak link is the paint on the line. Once It fails at any point it will spread. In your case the nut likely cut through the paint during installation allowing the nut to weld to the line.

When using machines to fabricate, steel lines have the advantage of rigidity they stay perfect from fabrication to installation so there are definitely benefits.

Nicop Is 10x easier for DIY so the advantages vaporize quickly.

Please see attached to see what failed on me.

[StephenVA]

Unions joints....

[andrewwynn]

I was able to detach the downstream side of the two front unions


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[2004bmwx53i]

[QUOTE=andrewwynn;1217590]I was able to detach the downstream side of the two front unions

I totally envy you!
This delayed my work for 2 weeks.

[nick325xit 5spd]

Originally Posted by 2004bmwx53i

If steel lines are that bad, why BMW uses it. Mind you, this line that I took out due to rusted connection nut to the end of the brake hose, was in perfect condition along the rest of the line. I had to use dremel grinder to scrape it off. This is after 18 years of salty road exposure. The weakest point seems to the nuts and not the steel line.

Mostly, I suspect, because steel lines are cheaper, and the ease of bending doesn't really matter for the factory.

I've had plenty of steel lines, including on BMWs, fail mid line.

Nothing is as bad as the idiotic GM uncoated steel brake line thing they used to do. Had to replace all the lines on my truck.

[2004bmwx53i]

Originally Posted by nick325xit 5spd

Mostly, I suspect, because steel lines are cheaper, and the ease of bending doesn't really matter for the factory.

I've had plenty of steel lines, including on BMWs, fail mid line.

Nothing is as bad as the idiotic GM uncoated steel brake line thing they used to do. Had to replace all the lines on my truck.

Makes a lot of sense. Thanks for the input.
Regarding your truck: What doesn't kill you makes you stronger!

[StephenVA]

The great news is that there are complete kits for the ones that go bad often like Jeep, Ford, Chevy etc, just zero for BMWs.

Had a Jeep Grand Cherokee master to rear to rear union on Axle brake turn into a flute. Every inch had a hole.

The reason why BMW lines go bad is external environmental issues and poor coating on the lines. On most other make applications it is internal to exterior failures, as who besides BMW owners flush their brake fluids?

[nick325xit 5spd]

Originally Posted by 2004bmwx53i

Makes a lot of sense. Thanks for the input.
Regarding your truck: What doesn't kill you makes you stronger!

GM also didn't paint the frame, they just dipped it in wax. We had to take the cab and bed off to coat the frame.

[2004bmwx53i]

Would someone please tell me what this black line is on the photo attached. It is located behind front left (driver side) wheel cover just behind the brake line/brake hose connection. It continues under the car alongside all other brake lines. The other end continues to the engine.
I can't figure out if it's a tube or an electrical wire. I was heating the brake line nut, the heat got to it and the outside cover got melted. I have to know if I have to replace/repair/ or just leave as is.
It's most likely a vacuum hose. I couldn't locate it on the RealOEM.
Any guidance will be appreciated.

P.S. Just found out one end is attached to the throttle body boot. So it must be a hose of some sort.

[oldskewel]

The fuel filter has an integrated fuel pressure regulator. That regulator vents a very small amount of gas vapors. Those vapors are routed all the way up to the intake.

I will guess that this hard plastic line is one of the lines in that path.