I couldn't find this written down anywhere so thought I would mention the fiddle fitting a new rear brake pipe to my 2001 X1.
I was replacing the old pipe only because the fitting near the caliper looked a bit rusty and the rubber a bit chaffed, and Im doing all the Cylinder/caliper seals
New hoses all over ebay are only around £15 so I bought one.

Its arrived but now I look closer find the Buell system has a rigid metal pipe leading from the master cylinder to a fitting which carries the brake light pressure switch. The hose becomes rubber after the switch.

The hose I bought also came with wrong threads for the banjos. Seller is sending new fittings. The brake light fitting I bought was another £12 (branded Goodridge rather than £2.50 Chinese).

Itll be fine soon.