Volvo: 240 DL 1989 brakes?, brake pad, rotators

Question
My brakes have been getting softer lately because they are old, but in the last few weeks I have been hearing a faint scraping noise from the front right tire when I'm driving and sometimes (only sometimes, which has me confused) I hear a grinding noise when I brake. I assume it's the brake pads or rotators but since these noises are not constant, I'm confused.

Answer
A grinding while breaking to me usually only means one thing, a worn brake pad has allowed a caliper to grind into the disc.  The fact that you only hear it sometimes is weird, but I would examine all 4 wheel brake systems thoroughly to find the problem.  Also, if you can feel a vibration through the petal while you are breaking, that is another sign you are grinding on one of the wheels.