replacing water pump

i have a 92 b-150 ram van w/ a 318. i just found a huge water leak and it looks like my water pump, actually it looks like the top of it. trying to locate it, i took off my fan cover, and it seems to leak out the top. more gush then trickle. my queustion is how do i take off my clutch fan from the pump. i took off the four bolts thinking they were for everything, but they were for the pully. the shaft has a huge hex shape. is it a threaded shaft? many thanks to all who answers me.

Yes it's a REVERSE threaded shaft. So loosen it in the opposite direction of normal.

You are going to need a tool to take it off. One for the large nut and another one for the four nuts on the pulley.
Auto Zone will loan you a tool free if you buy the pump from them.

I just used a strap wrench to hold the pulley (belt removed) and a large adjustable wrench on the nut. That took it off without a problem after the initial umph to break it free.

I'm glad you got it I didn't know what tools you had.