Sure looks like that band allows the pump chamber to come apart. Slick, try it. I'd bet the parts that the band holds together have a large O-ring for sealing. Most that would happen is the O-ring would have to be replaced. Also get a tube of silicone grease for the ring when you put it back together. And like Tenax said, you should not be getting big stuff to this point in the syetem.
Al