hi there. u r worrying too much. the fan works at the Computer preset temperature. the car specialist will link ur computer to theirs and he can change the "on-temp" for ur fan. i had mine dropped 8 degrees celsius. the normal running temp fo ur engine is between 80 and 90. about the leeking problem, it could be an overflow, it could be baddly tightened junctions (that really are easy to fix with a screwdriver). i hope this helps. good luck