I replaced the fresh water pump on our Jayco (2010 Jayflight 19bh) and the new pump often acts as though the fresh water tank is nearly empty. I put shutoff valves on the overflow tubes because they were siphoning much of the fresh water out immediately after fill - although there was still enough left that the pump should have been fine for a while. So, specific symptoms:
The strainer before the pump usually has 50-80% air space even when the pump is running.
Pump sometimes runs for a long time - shutting it off and then back on along with opening a fixture (then closing) usually gets it to flow better and shut off when the pressure builds.
Sometimes "spits" water and air.
I pulled the pump and it works fine when I put a short intake tube in a bucket of water and then open and close a valve on the output side. I'm worried that something is wrong with the factory mounted intake. Bummer is I can't get to it at all without dropping the underbelly mounted the tank which seems like a major project. Any thoughts???