if the viscous has seized it'll run all the time, and shift air - which is bad
if it's working correctly it'll still spin but shift bugger all air - which is good
if you are brave you can try stopping the fan whilst it is moving using a finger you don't use often or a thin stick, newspaper etc
this is a URL
Redirect Notice that doesnt work
link to a cheap (now) good flare tool
http://www.ebay.co.uk/itm/sykes-pickavant-brake-pipe-flaring-tool-/200796363667?pt=UK_Hand_Tools_Equipment&hash=item2ec0655b93#ht_500wt_949
James, on your text entry box can you see a little symbol that looks like a mountain range ?
click that then paste the URL of the image you want to display into it, and then, by magic
it's probably safer to jump on the handle, as you'll naturally fall off it - whereas by hand, if you aren't aware of the potential for hurt the inclination is to keep hold
depends how nimble on your feet you are, no more dangerous than jumping from a foot high - it's not like a prop that will come around and bite you
eat more pies