Shurflo 4008 water pump in a 2108DS Micro Minnie TT

[tinglett]

I have a question about the water pump in my Micro Minnie TT. I've figured out most things seen in the attached photo, including the strainer, selectable input sources (short hose for anti-freeze vs fresh water tank), a sneaky extra 10A fuse, the freshwater tank corrugated filling hose paired with a clear air vent hose, and of course the water output hose that comes out of the pump at the bottom of the photo into an ell fitting.

What has me a bit puzzled is that the pump briefly cycles a short burp about every 5 minutes. I'm assuming this is due to some kind of leak back since I haven't found any puddles around the trailer. One thing I'd like to rule out is a dirty check valve, but I'm not seeing what looks like a check valve. Is it integrated in the pump somehow? I was thinking a check valve would be needed to keep city water from flowing backwards through the pump.

One other thing is that I see it's bolted straight to the floor. Has anyone tried additions to the mounting to make it a bit more quiet? It isn't really that bad considering, except if it's going to keep burping throughout the night. If that's normal I'm going to need to figure out how to add an extra switch in the bathroom so I can keep it switched off normally. The noise would drive me nutters, not to mention the wasted battery draw.