1989 signature series brake failure

I have a 1989 Lincoln Continental Signature Series. When driving the brakes go out with no warning. I have to push REALLY HARD to stop. Sometimes it starts working and for no reason it quits again. The last time I drove it (in traffic) for about a half hour it was just fine, then it quit working. I continued to drive it for about another half hour and it started working again....BUT this time the front right side started to smoke like it was getting really hot or maybe brake fluid sprayed on the hot brakes. I parked it right away and not sure what to do.

My thought is that the accumulator is going bad OR the electrical pump may be failing. Your thoughts?