I just finished going throught all of this with the mother in law's motorhome last weekend trying to get running water. Last weekend we took out both motorhomes to a provincial park with no water hook ups and did a bit of trouble shooting, and found the inlet filter partly plugged and housing cracked. We got a new inlet filter on the weekend, and also added a shutoff valve between the tank and the filter so we can now remove the filter with out having to drain the tank, one problem fixed. We now have water leaking out of the back of the rv under the bathroom sink, removed the cover under the sink and found the hot water line came apart at a "T" , reinstalled that, problem 2 fixed. found another leak under the kitchen sink, the inlet pipe on the taps had cracked, another trip to the rv shop, and new kitchen taps installed, Problem 3 fixed. we also noticed that the pump motor was also kinda noisy, so i decided to seperate the motor from the pump and see if it was the motor or the pump, ended up the motor bearings where shot, but i had saved the pump from ours where the pump had failed on the sur-flow and installed the other motor in it place, now its quiet again. I found in our motor home that there was a factory screen in the bottom of the fresh water tank that had gotten plugged up restricting flow to the pump, which i punched out with a screw driver and then added a gate valve at the bottom of the tank and a screen after that a could again clean and get at easy if need be. You may also find too that if your battery voltage is low the pump may not be able to build enought pressure to shut off the pump as well ...
