RV plumbing. Strange plumbing set up

[Kadin]

I have an old 1973 Aristocrat Trailer and having some issues with the plumbing. Hope someone can help!

The problem is when I turn the water pump on, water just shoots out into the toilet. It is supposed to only spray in the toilet when you press the foot pedal. I image it has something to do with the valve near the foot pedal but who knows?

Here are some images. The pipe connected to the bottom right is the cold water in. The black thing to the left of that is the lever that is activated by the foot pedal. I did take it apart and it seemed like the seal in it was tight. Could it have to do with this other thing on the top that looks like a bell? Those hoses coming out of that are going directly to the toilet bowl.

As you can tell I don’t know much about plumbing but would love to get this fixed.

Any advice? Need more photos?

Thanks,
Kadin

 

[Terry]

That part with the cap may be a vacuum breaker to prevent a cross connection.

Or perhaps a "water valve assembly"?
https://www.rv-insight.com/RV-Toilet.html