Brake problems!

[crazybitch]

Any ideas why my brake pedal would keep feeling differently? sometimes i press it and no problems, other times it feels quite or very spongy! but still stops, other times it feels hard (no jokes boys please!) as if the vacuum pump is u/s any ideas?

[Gizmo]

May need a change of Brake fluid or could be air in there...may need to bleed the brake system???

Master Cylinder on the way out??