Hello everyone, first post but long time lurker. Last night i noticed a coolant leak coming from my truck on the ground while i was shopping. Was almost a 12" wet spot on the ground after about an hour and a half of sitting. After getting the truck home and letting it cool off for a bit i was able to find out where it was coming from. On the head in the back passenger corner there is a 45 degree spot that has a small hole, about 3/8" diameter. Is this a freeze plug and if so has anyone replaced