Ronnie, am I correct in assuming that the tractor in question has no coolant recovery jug? As the coolant heats up, it expands and if the radiator is full, it has to push some out. In most modern cars and some tractors there is a coolant recovery jug into which that coolant is pushed. Later as it cools, it draws that coolant back into the radiator so it stays full. But on those cars and tractors which have no coolant recovery jug, if the radiator is full, the surplus when it expands is just pushed out the overflow and onto the ground. When you're running at "normal" rpm, it will still push some out as it warms up, but you won't notice it if you're driving along. Then when you stop and idle the engine, there's a brief period of time that the temperature rises slightly because the coolant is not circulating as fast, and a little more is pushed out. On most vehicles without a coolant recovery system, if you don't add coolant, it will soon quit pushing any out, but when cool, it will have some air space at the top of the radiator. On the other hand, if you fill it up when it's cool, then it's going to push some out the next time it warms up.
Now that's my opinion or belief as to what's happening, based on the assumption that there's no coolant recovery system and without actually seeing the tractor in question. /forums/images/graemlins/wink.gif
