I have the Libec M20 and this weekend when I was using it I noticed that the leveler had lost most of the liquid in it. So there was no bubble in it to level the head. Is this fixable or can I get a replacement part?

Try to contact Libec. Here's the Home Page (http://www.libec.co.jp/english/index.html), in English. I would try to email them and see what support they offer. Post back if you have problems.