When I was 17, I had a brake line op at the bottom of an exit ramp. I learned the hard way, that the left pedal parking brake was not as effective as I would have liked, and when fully depressed, added some instability to the affair. I got it stopped between a dumpster truck on the right, and a concrete wall on the left. Right mirror needed replacing, but I got away with one.
The other issue with the rubber lines is when they swell internally.