corsair truck camper - sewer valves - near front of camper

I do not think you will be able to to a lot without taking the camper off the truck and removing the lower camper floor cover. But I have never seen a Corsair camper, so they may be different.

The forward location of the sewer dump valves sounds unusual to me. Where is the bath room, as the the black tank is usually underneath the toilet. And the rest of the plumbing runs to the rear, towards the sewer hose connection. In all the setups I know, the valves have always been close to the sewer hose connection.