Hi everyone, I was driving my 2004 BMW e60 520i and everything was fine. Then, at a stop sign, my brakes stopped working. I parked safely and found out all the brake fluid was gone. How do I fix this?
Thanks for sharing your question on this forum! To help people give you the best advice, be sure to include details like your car’s year, make, model, mileage, engine size, and whether it has an automatic or manual transmission. Good luck getting this fixed!
You’ll need to replace the line that broke. It’s probably one of the two lines running from the master cylinder to the ABS unit. Since one failed, it’s a good idea to replace both.
After fixing the line, make sure to wash the area right away. Brake fluid can ruin your car’s paint if it’s left on there too long.
Vega said:
After fixing the line, make sure to wash the area right away. Brake fluid can ruin your car’s paint if it’s left on there too long.
Good tip, thanks for pointing that out! 
The fitting on the line is crimped and not something you can repair. Ideally, you should replace the entire line. If that’s not possible, you might be able to cut, flare it, and add a coupling with a new section of line.
@Oaklan
These days, the cost of parts and labor for that might be more than just buying a replacement line or hose.
This isn’t just ‘popped out’—it’s a complete brake line failure. Maybe the brakes were stressed, like if ABS kicked in on a slick road, and the line was the weak spot. Either way, you’ll need to replace it.
That’s a serious brake line failure. Replacement is your only real option here.
You can’t just ‘pop it back in.’ The line is blown, and you’ll need to replace it or have it repaired professionally. Don’t forget to bleed the brakes and ABS afterward.
If you’re not planning to fix it yourself, you’ll need to tow the car to a shop. Replacing the line and bleeding the system are required.
Brake line *failed.
Failed*
You could get the line repaired at a hydraulic repair shop. It’s not a complicated fix for them—they handle this kind of thing all the time.
Just ‘pop it back in,’ no worries! 
Ray said:
Just ‘pop it back in,’ no worries!
This comment isn’t helpful. It might mislead the person who posted and cause serious safety issues. Let’s try to keep things constructive.