Just to clear it up, you don't touch, squeeze or smell the rubber brake lines, you replace them before their high failure rate blows on which is common on old hose on a hot day.

 

I've been working on Land Rovers for 35 years, never seen a Rover flex line blow out.
Clamping off rubber flex lines is an normal way, really the only way, of isolating sections of the brake system to determine where the fault lies.
I don't deny that the flex lines should probably be replaced, but it would be better to do the diagnostics with the old ones, then replace them.