I had a huge bubble in my Aquameter Galaxy compass that was driving me crazy. It seemed like it would be easy to put some more fluid in it and get rid of that stupid bubble. It's not! Find the leak is the first thing, and if you can find the parts install them. Then try to figure out what the dampening fluid is. (Mineral spirits, mineral oil.....) and then try to fill it while it's cold so that expansion is at it's minimum. And then burp it a hundred times. And then you still have a little tiny bubble that insults you every time you use the compass. If you don't have a bunch of patience and time, GET A NEW COMPASS. Next time I will..........