Brake master cylinder ?

Hi all, i've got a 2003 discovery TD5 currently not being used but regularly moved in and out of barn and around the yard, got in other day and red hand brake light stayed on, so thought i'd check brake fluid level but never got around to it, couple of days later went to move it again and brake pedal went straight to floor and no brakes, checked fluid level and needed quite a bit to top up, tried to pump brakes to get a pedal but can't get any pressure, no obvious sighs of leeks but not had a crawl underneath as yet, just checked on floor for pool of brake fluid but nothing there, anyone else have this experience ? suspect failed master cylinder but thought i'd get advice before i start stripping it down, cheers in advance

Paul

clutch cylinders can lose the fluid out of brake reservoir but not all of it , brake pipes at rear under body are prone to rot

Cheers mate, cars an auto, i'll have a crawl underneath and check rear brake pipes, thanks again