IF I had a motor home that was 2 model years old and a brake line failed like
you said- I would report it to http://www.nhtsa.gov/
The national highway traffic safety admin.
Save your old parts and take photos and document as much as possible.
IF you had flushed and re-filled your brake fluid at the 2 year mark as suggested
I believe your lines would have still failed.
You did say they failed just out of the 2 year warranty period.
The damage was already there by the time you got to 2 years!!
I had a brake line burst in an OLD pickup truck a long long time ago.
I was hauling a ton of sand in a 1/2 ton truck and it failed at a stoplight.
Thank goodness there was no cross traffic.
A 2 year old motor home should NOT have rusted brake lines especially
since you don't live in snow country!!