Buy "shimano olive kit", "universal kit for all shimano brakes".
Doesn't f****** fit, ruin the hose by repeatedly chopping 1" off untill you run out of barbs and olives, assuming blindly that you're just having a bad day mechanicaly.
Buy Shimano Bh90 (or whatver the new stuff is called) hose kit, remove from packageing, install to the lever, get to the calliper and it's a barbed fitting not the f****** banjo that XT brakes use.
-£25 so far
Bought this instead, bargain, and no brakes