Yes, the 201 chassis has a simple vacuum controlled water valve.
I think the water flow is off with vacuum on the valve. Pull the vacuum line off the valve and see if it moves. If vacuum is needed to close the valve, it will be open with the vacuum line off. Verify the two separate valve positions.
Don't assume just because the external pieces function that the valve actually opens. They are cheap plastic valves and they often fail in this manner.