Your not offending me at all. Safety is important. My mechanic is having his system serviced and since there's not a great need for a/c right now, he said it could be several weeks before he could charge it add some dye and see where I may have a leak. He suggested putting in one can with dye myself since the system was low enough to accept it. Of course I realized this am that I didn't know which was the low side. rather than call him at work, I figured I'd post here.