My '64 Cadillac DeVille had been sitting for awhile while I was travelling this summer and when I came home it had some issues starting. After replacing the plugs and the ignition coil, it was running better than it had in a long time but the brakes were sticking. I noticed the brake pedal was traveling a little farther than usual when slowing down. Soon after I noticed a hissing noise coming from around the brake pedal. Then I lost the brakes pretty much completely. I couldn't find any leaks from the brake lines or the master cylinder when I took a look around. Is my master cylinder the culprit, or does anybody have any ideas on what to do next? Is it possible I cracked the brake line removing the plugs?