There is a round hole under the pump that is most likely leaking. Check for the leak there. If leaking, the pump's bearing is bad causing the seal to leak. This is what happens on almost all waterpumps when they go bad, and yes they could make a churping sound.
As far as labor, it should take no more than two hours.
I hope this helps. Let me know if you have any other questions.
Tuesday, December 16th, 2008 AT 6:32 PM