I bought a low mileage (102K)2006 Buick Lucerne the other night. Very nice car. It has been sitting at least the last 4 months. The owner is in a nursing home and his son sold it to me. He said it had a recent brake job before parking it. I have no reason to doubt him. I drove it about 70 miles counting test drive and trip home. I did hit the brakes pretty hard before one corner. Everything worked as it should until I got about 2miles from home. Then I got a real soft brake pedal. after a couple more stops, I didn't have any brakes. I checked it yesterday. Reservoir was empty. I went down into the grease pit to check for caliper leaks. (First time down there since I walked into it and broke my foot the end of August). No apparent leaks at any of the calipers or lines leading to them. I refilled the reservoir and tried pumping them up. Did not get any resistance after 30 to 40 pumps. I haven't looked too hard to find where the fluid went! Is it possible that the master cylinder and or vacuum booster failed and the fluid got sucked through the engine? I will try harder tomorrow to find a leak. Thanks for taking the time to read this. I will post results when I find out what happened. Roy