I have a question regarding the master brake cylinder, on the 1980 Honda Civic I'm attempting to restore. When I acquired this vehicle, the brakeswere totally non-functional, and depressing the brake pedal produced a strange groaning noise from the master cylinder area. I later discovered that one wheel cylinder was missing and the fluid had been allowed to drain from that line. The other three lines were still connected and still contained fluid. However, the fluid reservoir was empty - but I don't know for how long. If it was empty to start with, it probably has been for the last several years the car has been sitting. Otherwise it's only been a couple of months. I'm told that the seals on the piston will dry up and crack in the absense of brake fluid, necessitating replacement. But should I automatically assume my cylinder needs replacing, or is there any way to inspect it or perhaps test it (while driving around in the yard, for example). I'd rather not replace it unless I had to. I am however replacing all of the brake lines, and the rear wheel cylinders, just to avoid problems down the road. Thanks for any advice.