Viscous Fan Clutch and Pulley

[viejo1221]

I have a couple questions about the Viscous Fan Clutch, and I realized that I had too many topics in my other thread. I'm learning, sorry.

How does it work exactly? When I first posted, I thought it wasn't working correctly because I thought that when you first start the car, the fan wouldn't need to spin. But after some more reading, my understanding is that the fan spins with RPMs at idle, continues to spin while driving until the Thermo viscous _______ (fill in the blank) reaches a certain temp at which point the clutch disengages and the fan spins free. So that when you're at highway speeds, airflow takes care of cooling and not the Fan with RPMs. Am I on the right track?

Haynes manual says that once removed the viscous fan clutch should be stored standing up. Haven't seen that anywhere else. Anyone know why?

What should I use to clean the front of the fan clutch that won't harm it? chowbow suggested to just use water, I'll try that tonight and see if I can get all that grease buildup off of there.

Lastly, I was putting the pulley back on to the bearing bracket and one of the 10mm bolts' head broke off. Should I just get 4 new ones from the hardware store? It's a new pulley but it didn't come with the 10mm bolts. I just thought that one of four bolts being different may cause a balance issue if they don't all weigh the same.

Thanks