[C320-list] water system hose clamps

[Koen Bennebroek]

I suspect we have a leak in one of the hoses leading
from the water pump to the stern shower, so I wanted
to disconnect that part of the system from the rest.
The reason I believe there is a leak is that our water
pump comes on every now and then without us running
any faucets. 

When I tried to disconnect the hose from the 3-way
clamp under the galley sink, I couldn't get it loose.
There's a cap that you can pry off with a screw
driver, then there's a spring ring you can push off,
but even then, the hose won't come out of the 3-way
clamp. Can anyone tell me how these clamps work? Is it
glued in there? Also, does West Marine sell the
in-line hose valves for these hoses (15 mm) (like the
in-line valves we have for the bow and stern tanks) ?

Thanks, Koen