Howdy! My name is Marvin. I have an older manual electric 5600. I replaced medium about 5 yrs ago has been working great. However now no brine draw, I went thru screen, venturi ,salt line etc. all good. I did find a couple of loose rubber seals around main piston. Is it possible with these being worn that brine tank wont draw? seems to flow water into brine tank even when supposed to be on brine draw. I'm pretty sure I answered my own question however would like confirmation if main valve stack seals can cause no brine draw and over filling of tank. Thanks in advance, have a Blessed evening!