Hello I hope you have heard of this problem and can help me.
When my water softener recyles itself and only then, I here a noise like it is shaking the pipes. When I go down to check on it, they really are not shaking but the noise is loud right at the softener. It seems to only happen when the water that backflushes is about to shut off and go to the next cycle. This just started not to long ago. The only thing that I did different in the plumbing department was to replace an outside faucet. One of those antifreeze type. I can't see where that would have changed anything, but Im no expert. What do you think? Have any ideas?

You might have knocked loose some debris in the piping and now its caught in the softner valves, that can also have all by itself. The rattle could also be a loose washer in the sopftner valves.

It is most likely air getting in the softener. It is probably accumulating a head of air in the top of the softener. Then, when it backwashes it purges it out. This could be coming from the brine line. The brine line connects the softener head to the salt tank.

Do you know make and model of your softener? If I had pictures, both close-up and distance, I can possibly isolate the problem.

What you might do is replace the little flexible tubing that goes from the softener control valve (aka head), and the salt tank. That tubing is frequently the issue. Sometimes it is the air check, which is supposed to not allow air to come into the softener.

Let us know.
Al

Make sure the bypass valve is pushed in all the way...