It has been brought to my attention that some drivers of older trucks maybe over filling the radiator when cold and then when the truck gets up to operating temperature the coolant is being pushed out the overflow. The trucks using green coolant typically do not have a secondary reservoir to catch coolant being pushed out due to expansion and you should leave approximately 1 – 1 ½ inches of head space between the top of the coolant and the bottom of the filler neck. This will allow the coolant to expand and not blow coolant out the overflow.
