So, I installed a new chain today, and since this chain has considerably less slack than the old chain, I had to adjust the position of the rear wheel accordingly.

But, when I was loosening up the bolt between the torque arm and the caliper, I accidently loosened up the wrong bolt - it was the one _on_ the caliper. I pressed the brake pedal down, and brake fluid leaked all over the rear axle from somewhere inside the caliper. No matter how much I torqued that bolt, it would still gush fluid until it finally started sucking air.

I'm thinking that I might have broke a seal in the caliper or something. Does anyone have any idea on how I can fix this??

Thanks... I'm still slapping myself in the forehead for being such an idiot.

There's a crush washer that goes in there; you probably just need to replace it. Don't over-torque the bolt.

Make sure you don't have a cracked brake line.