I rode in mid 80's weather for about 26 miles to get home Saturday. When I pulled in the garage and got off the bike I heard a weird sound and after getting closer realized it was coming from the gas tank. I slightly unscrewed the cap and could hear the air hissing from the tank. I loosened a bit at a time until it stopped. I put the cap back on and got a few things from the bike and uncrewed the cap just a bit again and even more air pressure. What the heck is going on? Most of my riding will be in much warmer weather and longer distances when I get moved to Midland in June, so I want to figure out what the problem may be and if it is even a problem or me just fretting.