Water softener won't draw brine

Discovered water wasn't soft. Here's what I've done. Disconnected brine tube from tank float, it is pulling vacuum. Stuck tube in cup of water, draws fine. Replaced the air check valve tube part on the float valve assembly, thinking that the check ball was stuck. While doing that, discovered that there was a lot of salt mush on the bottom so I emptied the brine tank completely and put in new salt. Still doesn't draw brine.

When the brine draw starts, water does flow properly into the tank for several seconds.

Softener is only a few years old. Fleck 5600SXT valve.

So now what?

 

How can you tell?

I don't know what could cause the flow to be only for a few seconds.

I would clean the injector (two pieces) and the injector screen, but I can't see that causing that limited-time suck.

I would consider putting a tee into the brine line with a combination vacuum+pressure gauge. I have not heard of that being done, but it sure sounds like a good diagnostic. Brine will not be easy longer term on a gauge with metal parts inside.

 

To clarify, I may be wrong, I believe that water flows into the brine tank for several seconds to flush the line of air? Then it draws. I'll go verify that...

 

Not normal. There should not be more than a trivial amount of air in the brine line in normal conditions. Air in the brine line would indicate a leak. But other than dissolved gas coming out (that trivial amount), there should not be air.

 

Water does flow into the brine tank for about 5 seconds, then is switches to suck. I'm guessing that's to avoid an airlock in the tube? Anyway, it's working now. I think when I checked the brine draw this morning, I was too impatient. Now, after about 15 minutes, I could tell the water level had dropped. Thanks!