So the last time I drove it, everything worked fine. I go out last night to just drive and I have no brakes. Pedal all the way to the floor. I check the master cylinder resivour and its empty. There is no sign of a leak any where. Might sound weird but I've crawled under and checked each wheel visibly, nothing. I've never experienced anything like. Any ideas?

 

Do you have ABS?

Master cylinder can leak into the booster.....

 

Booster is empty

 

If it's leaking into the booster it is quite possible that the brake fluid is getting sucked into the engine.

 

No sign in the vacuum line. But how would know?

 

Fluid disapering.