The fan is a tight fit on the hub, especially if it's been there a long time. Soak the area with penetrating oil and wiggle the fan blades side to side to break the rust loose. Be careful not to bend the blades or gouge the radiator fins- - - -it's pretty close quarters in there.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!