coldsteelva
Veteran Member
I think you are actually speaking about the COOLANT OVERFLOW TANK, not the radiator. The radiator is only full or it's not and has no markings. It should be full of 50/50 coolant up to the base of the neck for the cap. The translucent bottle under the hood has a low mark and a high mark. Fill this to the halfway point between. When running in hotter weather, the fluid will expand from the radiator and push into the overflow tank; when it cools, the radiator will draw it back in. If too much coolant gets displaced it will reach the overflow tank's own overflow hose which daylights below the tractor and that coolant will be lost. After 6 years, other than the fact that it should have been changed, you will be losing some volume to evaporation and overflow - it's perfectly normal. Not being totally sealed prevents blowing out the radiator cap.