Water leak inside 91 Pace Arrow soaking carpet.

John you never said what toilet you have but assuming it is a Thetford you can get to the valve if you depress the foot pedal. The first time my valve leaked I replaced it with an O ring which lasted about 4 years then started leaking again. The second time the o ring did not fix it and I had to replace the whole valve. It was less that $50 if I remember correctly. The toilet is held on with 3 or 4 bolts and nuts at the base.