My water softener has stopped drawing brine. For the last several months, the capacity has been significantly reduced. It was still using salt, but it seemed to use less salt than usual with each regeneration. Now, however, it seems to have stopped drawing brine altogether. The softener is the style with separate resin and salt tanks. The control valve is one of the Erie 541 valves. It's not stamped anywhere, but in all the research I've done trying to figure it out, I'm pretty sure it's the 541N18. As I was trying to figure it out, I loosened the fitting on the brine line at the salt tank and found there is pressure there when it's regenerating. Shouldn't there be a vacuum there, rather than pressure, when it's supposed to be drawing brine? Any thoughts on what I need to do to get this working again?