Help! I'm doing a cooling system flush and I'm having trouble with the block drain. I can back it out to drain some coolant but it doesn't turn more than 3/4 to 1 turn. Now when I tighten it in coolant still drips(without any system pressure). Should I crank it out (lots of turning effort) and replace it. I'm worried about breaking it or rounding over the corners. What does the other end look like? I'd like to remove it completely for better drainage and to get all the rest of the junk out. That is the idea anyway, right?