Bob
Hard to say how hard it is to swap out. It appears that SOME check valves come with the complete plastic housing (with door & lock). My city water connection appears to be part of the plastic housing. Should be an easy swap. Stronglt suggest you carry a plug for that city water connection. If that check valve goes south you will hae ZERO water pressure from the pump. Could end up cutting a camping trip short.
Look at the backside of that city water connection while connected\leaking to see if it's also leaking on the backside.