I bought a Thruster backup valve for my Kreepy, since it always gets caught on the shallow end steps. However, I bought it used on craigslist and don't have directions. I can't find them anywhere on the web. Does anyone have a pdf of the directions. I am most interested in how to attach it. Does it attach directly to the cleaner, or do I move it back a couple hose sections -- maybe behind the weights? It seems really heavy, and when I attach it between two hose segments it sinks.