There is nothing like a ending a great weekend of mountain-top camping, and finding that when you go to drive off your leveling ramps the brake pedal hits the floor!
Originally I had thought that I must have kicked up a rock to damage the brake line, but I now attribute the break to my long tall T1N Sprinter body flexing the old rusted lines while traveling up a very rough unpaved trail, as the break was in a spot that nothing could have bumped it.
The lines fail where the clips holding them to the body rub and flex damaging the plastic coating allowing them to rust out.
More concerning was the fact that with only the brake line was damaged, I was completely without brake pressure for all 4 wheels.
I was unsuccessful trying fold and crimp the line, too old and brittle. So, I had to cut in and add a temporary piece and did a gravity bleed to that caliper to get back home.
I ran new lines using Nickel-Copper tubing, which I felt was much easier to work with than the steel lines, and yes I did check with the dealer regarding new lines and they do NOT come pre-bent, so why bother!
You'll need a bubble flare tool to do the job correctly, I also purchased a tubing reamer and plier-like bending tool for the job.
Since my 2002 had what I found to be a frozen/inoperative rear brake proportioning valve, I was able to form the new lines without it, and it must have been stuck in the "empty van" position as the van stops even better now. The ABS was unaffected, even on loose surfaces I am not getting any wheel lockup without it.
I did run down to near empty and dropped the fuel tank to run the lines, as I wanted to keep them as close to the original positions for protection while driving on unpaved roads/trails where I camp.
The most difficult part, to me at least, were the bends closest and connecting to the ABS unit.
I used a Motive power bleeder along with my D.A.D. tool bleeder function to remove the air bubbles.
FYI, if you do get stuck with a leaking line, the best way to get home is to plug the leaking line right at the port where it comes out of the ABS unit. I purchased and tested brass plugs used to block off unused master cylinder ports on dune buggies.
Our crafty pal Aqua Puttana fashioned similar plugs from the old threaded brake line hardware with a screw threaded into it... and soldered them shut as well?
Here is a Forum link to Vic's thread on brake line replacement:
https://sprinter-source.com/forum/showthread.php?t=26307