I need help with Co2 tank D:

Well I recently I bought a tippman 98 custom. Last week I put in the Co2 tank and dry fired a shot to see if the gun worked. It worked perfectly. When I unscrewed it it started to spill out for some reason. I quickly unscrewed it. Yesterday my box of 2000 paintball rounds came and after school today I wanted to test it out. I put rounds into the hopper, then screwed on my tank it started to spew out Co2 like crazy with anm extremely loud hissing sound, I unscewed it and tried again. This time Liquid AND Gas Co2 came gushing out of the top and I got SEVER wind burn. Please help me D: Why is it doing this?

Yep, you broke an oring and you will break many more in the future all you need to do is go to walmart or where ever and pick up a pack of about ten or so. Also as tallen said next time you go to tank your tank off, fire your marker a few times to relieve the pressure pushing on the tank as you try to unscrew it. Doing this will save you quite a few orings in the future.

Mack wrote: Putting a very tiny bit of oil on the o-ring before you install the tank will make it (the o-ring) last longer.

This is a good idea, and I also (it's kind of been said already) unscrew the tank slowly until you can just hear some co2 leaking out.  Then screw it back on just a little bit, and shoot until the gun is uncocked (if it takes for than 3 shots you probably need to take the tank off further).  It usually only takes a shot or two to get the gas out of the lines.