Moisture trap questions...

I have two moisture traps.  One is at the very beginning of my air hose that connect to the compressor, and the other is at the end of the hose and connects into my airbrush.  However, i am still getting water in air.  I have had the above rig for a few months and have had no problems, but now all of a sudden i am having issues.  Could the traps be full?  How do I empty them (an embarrassing question)SHould the compressor be running while i press the buttons? the water sprays all over, but the moisture is gone.  It usually works, but i am afraid i will damage something (like an O ring) is thet the right way to do it?  I have tried pressing the little button without the compressor running, but nothing happens