Does anyone know the correct or best procedure to flush and fill the cooling system on a 2005 Ford Explorer with the 4.0L engine? Start to finish instructions would be great, I just want to get it right. I've checked around at this site and couldn't find any instructions for this procedure and my engine type. Also, besides removing and installing a new "thermostat", does anyone recommend the fail safe type of thermostat? Currently, I have no leaks and the hoses look okay or have any heating issues as far as getting heat into the vehicle, but the coolant appears to be original factory (pinkish red in color) with 84,480 miles on it and it's time for a change. Thanks to all who respond.