Certainly every five years.
I do not know too much regarding mileage, but to me, brake fluid is something that not so much wears out as absorbs moisture.
I think if you live in a arid climate as I do, five years is OK; hot and humid, I would say every three, as what you are trying to do is avoid corrosion.
I presume brake fluid like coolant, contains anti corrosion inhibitors and that they must break down over time; hence change both the antifreeze and the brake fluid on some sort of regular schedule.
As to the brake hoses, I might go say ten years on those. The "rubber" hose stuff is better than it used to be. Also usually brake hose starts to weep rather than just split wide open so you tend to get fair warning - particularly if you are changing the brake fluid.
As to what fluid to use, per Bodsy's Brake Bible, the brake fluid is as follows. The LR Spec is SHELL DONAX YB DOT4 ESL FLUID. Otherwise, use a low viscosity DOT 4 brake fluid meeting ISO 4925 Class 6 and Land Rover LRES22BF03 requirements; ISO 4925 is the key if you can’t find the LR Brake Fluid.
The Brake Bible is available per the link below. Due to blocking, replace the *** with disco3 co uk and put periods between the words. Look for the latest version, 1.6a at the time of this post.
http://www.**************/gallery/thumbnails.php?album=4184
