#5939 burns slightly radical replacement block because PO melted original @ 2,000 miles or so. Works great for me, but I bet an owner who wanted something closer to factory would sure wish a LITTLE money had been spent on a bleeder (if that was problem. Could have been fans...). Thermostat bleeder doesn't hurt anything. You can make your own less than $10. Is one of the few things on car easy to reach. Makes changing antifreeze fast and easy. Question isn't "why", is "why not". And isn't it funny that people will spend $hundreds on "fan fixes" that may not be needed (WooHoo, ANOTHER message thread), but not even $25 on a fluid fix of similar utility. Bill Robertson (airport metal detector enemy #1) #5939