I have 12 year old Northstar 1 HP pump. I have navigator vacuum and skimmer on a valve which I can adjust so I can provide more suction to one or the other if the solar is on. Over the past 30 days the valve has to be almost 100% on the navigator to work properly then I get no suction in the skimmer. The water in the pump basket is about 1 inch from the top of after turning the pump on and never seems to reach the top. I have pulled the motor, cleaned and lubed, pulled filters and found cracked manifold and top that attaches to the 4 filters and replaced both parts. With all the above work I am still having the low suction problem. I am also noticing very low flow from the returns. I am out of options unless I replace the pump. Any help would be greatly appreciated.
13,000 gallons, Northstar 1 hp pump, hayward cartridge filter, above ground.