I have a '77 280z, previously the car sat around for about two years without being moved or started. I got it running again about three months ago with a couple fixes and got the brake fluid flushed in the process. About two weeks ago the brakes ceases up on me when I was driving around. It happened pretty slowly, it wasn't an abrupt stop. A couple days ago I replaced the calipers and pads in hopes that would fix it. Now I'm getting almost no pressure at all. There are no leaks in the lines that I can tell. Did I mess something up or am I missing something?