water pump leak, faulty??

[fongo]

Hi everyone. I noticed shortly after putting a high performance alternator (96 A) on my 93 GT, I began to notice the car temperature gauge was above 220C (all the way up) just by runnign the car idle after a few minutes. After inspecting under the hood, i noticed a leak from the lower radiator hose (into the water pump). I checked the hose and it looks fine (make sure it was tight also). The radiator is clean and no leaks (haven't done a pressure test though hmm..). I've also replaced the thermostat (although it seemed fine). Also after I turn off the engine, I hear a 'boiling' sound coming from underneath the thermostat.
I need some guidance on finding out if I need to replace the water pump or not, or is it something else.
Thanks.
fongo