Okay Today’s video if you remove this retainer nut to pull up the fill valve. Of course turn off the water first but this is what you want to do is. Turn the water on part way to push any sand and soil out. Sometimes what causes these toilet fill valves to go bad is a repair. An underground repair.
Resetting the new one back on the deal and than you just need to slide the retainer clip back down to lock the top half of the Fluidmaster fill valve into place.
Turn the water back on. Check for leaks and verify that you get a good flush. and you’re all set. It’s a nice easy way to prevent getting called back. If there is soil and sediment or any kind of debris. This just clears the line so it is ready for the new fill valve.
Here is an https://amzn.to/2LybtV0(Amazon Link) to the Fluidmaster fill valve and flapper.
It is also a good idea to change the flapper at the same time as that can get you called back as well!