fresh water pump runs but won't prime and push water

ScottG wrote:
I've had this happen three times over the years. In those cases it was caused by the pump sucking up some tiny piece of debris. Take the head off and rinse the parts off under some running water (irony!).

This must be what happened to mine once. Was all set to replace it, but we drove to another campsite first, and then it worked when we got there, and ever since. The drive must have shook out some debris somewhere.