Air Check - New Style ( kit 1032417 = Air Check Kit, 1/4" Male ) used from about 1993 to present. Can NOT be used in place of the old style ( see part # AP36F ).
Used only on late model Autotrol 155 and all 255 water softener valves.
The part number on the Air Check body is listed in some manuals as 100C142-001 and some as 1031939.
Cross reference part # 1032416 ( 3/8" not sold ) is listed as 1032417 in newer owners manuals for this Kit having 1/4" male thread output connection most commonly used,
( 1 ) clear air check body, with 1/4" male threads
( 1 ) black floating ball,
( 2 ) long screws, o-ring,
( 1 ) tube of silicone.NOTE: You do not need to turn off the water, as no pressure is on the air check ( except during Brine Refill ).
You will want to "purge" the air from the chamber and the brine tubing before running your first full regeneration.
see this FAQ article on the subject -
Brine Refill after Autotrol 155 or 255 Repair - Purge Air from the Valve head, Brine line & Air Check
Be sure to use Teflon Tape or similar product ( like our Lock Leak ) on the male Threads of the Air Check ( where the female fitting must thread on to ).
It is NECESSARY, or it will develop an "air" leak at the connection.
AND if your Salt Tank already has an "air check" as part of the Brine Pick Up Assembly ( often with Float Shut Off ),
then you can LEAVE out the black rubber ball when you INSTALL the clear Air Check body to the Tank Adapter of your Valve.
Old 3/8" compared to newer ( one we sell ) is the 1/4" male version,Air Check Autotrol Old 36F or Newer Style - How to Tell - How to Clean