Pumping water/dry camping

[Texas_Two_Stepp]

My new rig does not have an separate external filler for the fresh water tank. Unlike my old rig I have to connect to the city water inlet. When hooked up to city water I can fill the fresh water tank with no problem; however, when trying to pump into the city outlet using my 12v pump and water tank in the back of the truck it’s another story. I have a Shurflo 4008-101-E65 12v pump I recently purchased for this purpose. This morning I pumped about 40 gallons in to the fresh water tank on the rig and it took an hour or so. The pump seemed to be operating smoothly but the hose on the discharge side seemed to be cavitating. When I took it loose from the city water connection and let it flow on the ground it did better but still not 55 psi. I am using a 25'x5/8" suction hose and a 10'x1/2" discharge hose.

The Shurflo house pump that came with the rig has a clear tube you can use for sanitizing the fresh water tank by resetting some valves so I tried using this pump. Observing the clear tube I could see that it was not a continuous flow of water, but had a lot of air. I have checked all the connections for tightness and I know I have good voltage. Two different pumps, same results. What is happening??

[12th_Man_Fan]

In my RV there are valves that have to be turned to the proper setting for the water to flow into the tank. I'm sure you would have noticed this but I just wanted to make sure. When I am filling my tank from another container it uses the onboard pump to draw the water in.

[old_guy]

did you use teflon tape on all the threads,or it could be something as simple as needing a new rubber washer in the fill connection.

[dbbls]

You need a shorter and more rigid intake pipe. Make it as short as possible.

[Old-Biscuit]

Once pump is primed and pumping water flow should be steady....
You are sucking air in on suction side of pump...cracked fitting??

Also when pumping in thru city water connection, remove the screen/washer and just use a garden hose washer so pump doesn't have to force water thru screen.

On the end of pump is a pressure adjustment screw....turn it 1/2 turn clockwise to increase pump discharge pressure. Do Not turn it more than 1 1/2 turns total.