Water doesn't go back into dispensers after coming out

What I expected to happen was...:
When I flip a lever connected to a dispenser with water in it, the water would come out. Using lever again, would make the water go back into the dispenser. 

What actually happened was...
The water would come out, but it won't go back in.

Steps to Reproduce:
1. Connect a lever to a dispenser with a water bucket inserted in it.
2. Flip the lever activating the water coming out.
3. Flip the lever once more.