Based on our and our customer's experience, Backwoods compiled a set of commonly needed field service kits for the Aquatec SWP-4000.
A decrease over time in the volume of water being delivered is a likely indicator that there is wear on the valves and diaphragm in the pump head.
This kit includes the valves/housing as well as two small outlet flaps. The valve housing assembly(VHA) is one of two pieces that are commonly purchased together. Typically the Lower Housing Assembly(LHA) containing the diaphragm and wobble bearing will be purchased and replaced at the same time.