Originally Posted by charliej
DO NOT push in the check valve at the city water connection on your trailer. This will ruin it and make it inoperable.
Can you advise of any documentation to support this statement?
With the pump off, as long as you don't dislodge or damage the O-ring I fail to see how pushing in the check valve will damage it. After all, when you hook up a hose the water pressure pushes it in all the time. Of course if you jam a ice pick or something like that in you probably will damage the sealing O-ring, but pushing in the plastic center with a finger should be OK. Lots of people do this to get water in the line to drain (where the capillary action would otherwise leave water in the line near the valve or in the valve). Others use air pressure to do the same thing, and that pushes in the valve also.