There is a seap hole on the bottom of the water pump. Very small amounts of water will escape if the bearings to the shaft are bad.
I suspect that what your hearing is the bearings in the waterpump input shaft. Makes sence since it gets louder the hotter the car gets.
Has for the pulley... The last water pump I changed on one of our cars came with a pulley, so... I don't know what to tell you there. It is possible that if you had to press a new pulley on the new water pump and it was not done right, you could have damaged the bearings. Hince the premature failure.
Good luck -
