About a week ago, I was doing donuts and burnouts and once I calmed down and took it easy, I noticed my brake pedal a little soft. Thought nothing of it and kept driving home from the area we were in. When I got back to around my house, the pedal was nearly touching the floor. Ok, somethings wrong here. Popped the hood and check the resivoir...empty. Got the shop light out and checked anywhere I could. Followed the lines front to back, checked the front brakes...checked the rear brakes...nothing. No drips or leaks anywhere. Had the car on a lift today and checked it all over again and still nothing. And now it's not losing any fluid after a week of driving it off and on. In fact, the brakes work fine. What gives? Internal leak in the master cylinder? I had that problem last year with my jetta but didn't think the master cylinder on our cars would last that long, let alone still work.

 

This may not be your problem, but I have seen master cylinders leak into the power brake booster. If there was no visible leaks anywhere this could possibly be where its going.

 

I bet that's it.

 

It is also possible, but unlikely that it could have been leaking into the interior as well. but im sure you would have noticed a wet floor.

 

maybe it was the fluid fairy...