Your coach's fuel tank, sending unit and hoses are easily accessible from the driver's side. You have a "dead panel" (no latch on it) on both the driver's side and passenger side where your fuel fill doors are located. Those panels have two screws holding them closed at the bottom edge. If you look under the coach, you'll see the screws. Remove them and the entire panel, which is hinged at the top, will lift up. Use a broom handle to hold it open. Once the driver's side is open, you'll have access to the sending unit and fuel pick up tubes. You can inspect the hoses and connections.
Side Note: If you look at the sending unit, it's made by Centroid. It's adjustable. Most Monaco fuel gauges are never correct, usually they don't go to FULL, or more than half empty at the HALF point. There are a couple of adjustment screws to make changes. This is a topic for another time, but something you should be aware of. If you ever want to make the adjustment, PM me.
Centroid