Airlock creating vacuum?

I brewed an English bitter yesterday, everything went fine. Mash, sparge, boil, cool, etc. all went fine. Filled my airlock with vodka as I usually do and into the swamp cooler. I wake up this morning and switch out my frozen water bottles only to notice over half of the vodka is now missing. I assume that I just didn't fill it up as much as I thought I did and refill to where it should be. Fast forward to this afternoon. I go to switch out the bottles and once again my airlock has about half the vodka I put in earlier. While examining it this time I accidentally bump the airlock (3 piece) and the whole thing drains down into the carboy. I have refilled once again and I am just wondering what is going on here? Normal? Problem? I have no idea.

It sounds like you closed it up while it was warm, and it's cooled off now. Since the inside is cooling, it'll make a vacuum. Pull off the airlock now that it's cooled, and stick it back on. It'll equalize.

I just thought of that when I was typing it up. Hopefully that works.

Yooper's right, your brew was warm and the cooling effect lowered the pressure inside you primary. I usually leave the airlock off for several hours with a cloth or something else to cover the opening (so no flying nasties get into the beer). After a few hours of additional cooling, I put my airlock in place and have had no problems.

Salute!

Yeah, sadly I figured it out right after posting. I havn't had any problems since. Now I just wait for fermentation to start.