I have read last year about some cases that the fan clutch bearing and/or the water pump had play. By this the fan also had play and damaged the radiator. On another board in USA I also read that one of the fan blades damaged the hood after coming off.
On my website there is a German language tech explanation about car parts. That also explains how the visco clutch works. Here is the link. Under the pic there are German words like Motor kalt etc. Click on these words and you see that the pic will change to to cold, warm etc.
click here.
The water pump is also available on the after sales market, cheaper than from the dealer.
I changed my water pump so far once and the total mileage is about 65K.
If you want to change the water pump, on my website go to evansweb and /or to gale's page.