F2100e radiator

[BrisMatt]

Hi, does anybody know what the 3rd radiator hose does on my F2100e mowers radiator? It is at the bottom, with the drain tap, and connects back to the engine. It is a smaller diameter hose than the two main hoses. I have attached a photo of one for sale on ebay. You can see the 3rd hose at the bottom.
Thanks Matt

 

[TimAT]

This is from a F2560, but your F2100 radiator appears to be pretty close to the same.. #180 is the hose that connects to the small port, then the drain valve, (150-160) and then to the block, (210). It's all to drain/change the coolant as far as I know. There may be some circulation when it's running, but as small as those hoses are, I suspect it would be minimal.