I agree with SoundGuy, there's nothing wrong with the pump, it's the vibration that radiating through the rest of the camper.
I had a similar problem with my last Camper (Keystone Springdale). Fortunately, the pump was very easy accessible. I unscrewed it from the floor and bought a rubber (foam) type front door mat, like for your front porch at home. I cut a couple squares out of them, stacked them on top of each other, then put the pump on top of that. I then screwed the pump back to the floor, through both layers of foam, and did not tighten rock-solid hard, but left if somewhat loose, just enough it would not move around or shake loose when in use or when traveling down the road. That solved a great portion of the noise. It was reduced greatly. It still made noise, but nothing like it was originally.
My current camper has the pump attached to the side of a wall. Between the pump and the wall, is carpet. I think the carpet absorbs most of the vibration. The pump is right beside the bed, and we can barely hear it when it runs. It was in an enclosed box that looked like a step. Funny, when we looked at the camper at the dealership an then did the walk through, I wanted to know where the pump was. Even the dealer had trouble finding it because it was so quiet.
Cushion the pump and anywhere you can see pipes, wrap some foam or some insulation around those spots that touch anything. This will greatly reduce the vibration noise.
Nothing wrong with your pump. You have a good pump.