No Brakes on my 407

[Nick Challacombe]

Good day fellow Bristolers.
I went to remove my 407 from its garage and it started first turn, put my foot on the brake pedal and it went straight to the floor. Looked under car, no sign of a leak. Undid big brass filler nut on the lockheed master cylinder, no brake fluid at all.
Moved car out of garage which has a tiled floor and drip trays, no sign of brake fluid. I filled the reservoir and pumped the pedal and had some resistance but on releasing the pedal air bubbled up out of the reservoir. Still no sign of fluid anywhere.
Any ideas, has the fluid been sucked into the servo? or the vacuum tank , I am baffled, the fluid I put in the master cylinder is still there, I can still pump the pedal and get resistance and the brakes hold but when I take my foot off the pedal air rushes out of the reservoir. No sign of damp on any of the calipers.

Please help, Nick Challacombe.