2002ARki

I have 2004 allroad quattro, I noticed something strange with my brake. When I start engine I always push brake pedal, but this morning I noticed the pedal is very hard. And after engine started brake pedal goes to floor like always the pedal travel was not so long. And then after 1 hour drove, I parked at the shopping mall and spend 1 or 1 and half an hour, the brake pedal feels the same, it was hard to push. Is this a vacuum leakage from brake booster or related hoses?