Does anyone know what the symptoms are when the flat seal on a Kreepy Krauly classic (i.e. the large rubber "starfish" disc) is worn out? My Kreepy seems to work okay, but I started out with a used one (it came with the house), so I don't have a point of reference to how a "new" unit behaves/performs, and I'm wondering if replacing the seal (the flat one for concrete) would improve performance at all. I replaced the foot pad recently (is was fairly worn from rubbing on the concrete), so I'm thinking that the seal may be worn as well, but I'm not sure what the symptoms are when the seal needs replacement. Are there any telltale signs I should look for -- i.e. performance characteristics that may point to needing a new seal?