i have a hayward de4800 which i plan on cleaning this week. so upon further inspection i realized the filter head missing a Pressure Gauge, Relief Valve/ Gauge Adapter Assembly and o-ring, these parts are required i'm i certain right to relieve pressure or is there any work arounds without the parts. And yes i did buy some replacement parts. oh and how do i work a Slide Valve Assembly to rinse and backwash. and for the record, none of this was our fault but a foreclosure house.