Just an update on the story of my mysterious brake failure in France. The shop have now examined the brakes and replaced the pipes. It turns out the end of the pipe was still in the block connector above the axel. It had snapped off directly behind the flare, which explains why the brakes lasted for 1500 miles before they failed. It still does not explain how it could have happened at all. Even, if the pipe was flexing, I would have expected it to break behind the union and not within the block itself where it was held tight.. For what it is worth, the lines were not pure copper but cupro-nickel which is far stronger. I can only assume the pipe was damaged or weakened behind the flare before it was installed. The guys at the shop are as mystified as I am, but at least they replaced the lines without argument and we parted on good terms. All the same, I will be even more cautious than ever about checking my brakes from now on. Best wishes, Tony V.