Thanks! Yes, it's a model 310. I'm having a hard time understanding what I'm
looking at. Here's two pictures.
This is where the pedal inserts. You're looking at the end if the ball-valve arm. What are the two white things? (Note that there has never been a "hard connection" between the pedal and the valve. I had thought there was a spring connecting it.
This is the inside of the pedal that plugs in to the previous picture. The spring is just the pedal return I think.
I guess my next step is to try and remove the valve. I hope I don't drop it into the tank! From what I read in my Dometic manual, it sounds like it should pull out from the top.