Disco 1 brake problem

[GJM]

The brakes have failed on my 1995 DISCO the pedal has has no pressure unless I pump it allthough there is no loss of fluid .When depressing the brake pedal with the engine runniing there is what I can discribe as a whoosing noise which does not happen when the engine is not running I have checked the non retunn valve and its ok could the problem be with the servo or the master cylinder or something else also are service kit available for the master cylinder

[kawabud]

Check the pipe that leads from the servo along the top of the bulkhead to the inlet manifold. There's a T piece with a smaller bore pipe leading off it.
Is it connected?
These are all rubber pipes i'm talking about and even though the small bore one looks sound, it could have split.