Re: 96 150 water pump problem
Two common errors possible during reassembly
Impeller key displaced and the impeller is not turning
Water transfer tube not plugged into the water pump
Some years the water p tube does not flow until the t-stat opens.
Before pulling the LU off and checking the pump, try removing the t-stat and starting the motor (on the hose of course) 30 seconds should show if there is water flow or not.