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Rebuilding the Autotrol 255 Valve Body

The expected life span of the Autotrol softener control valve is 20 - 30 years with a few minor repairs along the way. The Flapper Valve Discs in the valve body generally need replacement after 15 - 20 years. However, if your system is on a chlorinated water source, the Flapper Valves ( part # 1000250 ) will need replacement much sooner ( 5 - 10 years is common ). On chlorinated water supplies it is also necessary to replace the Flow Control Ball ( part # 4F, or # 1030502 ) which sits inside the Backwash Plug on the right rear of your valve. In severe cases it made be necessary to replace the injector ( # 28F-BB, 0r # 1032971 ) also. There is no need to change other parts or o-rings unless you have a leak.

Autotrol Flapper Valve Positions

The flapper valve discs can be replaced by removing the 12 screws holding the top plate on ( you need to remove the cam and the timer housing first ). The flat springs pop out of the top of the valve discs. A pair of needle noses pliers helps with removing the springs ( and popping them back in place ), and also with pulling the valves out of the valve body. It is a fairly simple procedure.

PLEASE check carefully that the area where the valve disc "seat" is 100% clean, and be sure to Install the Discs into the Valve Body, and THEN lower the Top Plate on top. The Valve Discs must all be INSTALLED and SEATED first, for best possible results ( less chance of problems or leaks ).

The only other "tricky" part is to be careful putting the 12 screws back in. The screws are self tapping. I recommend turning them slowly in reverse until you feel them drop into the thread groove, then alternate tightening them down. Do not over tighten, since you are screwing metal into plastic.

Also, this "Tear Down" Video might help you understand how to take a part the 255 valve.

Autotrol 255 Valve Body Rebuild Kit:

1) Set of Flapper Valve Discs part # 1000250
1) Injector Cap part # 1000269
1) Injector part # 28F- AA, BB, or CC ( based on tank diameter )
1) Injector Screen & Cap part # 1000226
1) Brine Control part # 1F-19, 1034263
1) Backwash Plug part # 25F- 7 - 14 ( based on tank diameter )
2) Flow Control Balls part # 4F, 1030502
1) Tank Adapter O-rings ( 32F,(4)35F,37F ) part # 150A129, 1001404
1) Silicone Lubricant 1 gram

Our Kit Part # AP255RBK


A much easier solution is to purchase the complete valve body either with a new 460TC timer and Camshaft as the K-5 or just the complete valve body as the 24NC.

440 Timer Repairs

An obvious problem that can occur is for the timer motor to fail. The motors turn at 1 rpm, so it is quite easy to tell if it is turning. A more common problem is for one or more of the drive gears to strip. Removing the Tripper Arm screw, the Skipper Wheel screw and the three cover plate screws will gain you complete access to all components for careful examination. It is easier to work on your timer housing is you remove it from the valve body ( pull out "flag locking pin, slide power cord out of it's retaining slot, unscrew Cam Shaft Bearing at rear of Cam Shaft, and then pull housing straight up )

Common Gears that Fail
1. Tripper Arm Gear # 99F ( 1031756 )
2. # 7 Black Gear # 420A43 ( 1031554 )
3. Red Knob Gear # 106H ( 1001582 )
4. #8 Black Gear # 420A44 ( 1030844 )

Also the "Out Put Connector" # 21E ( 1031496 ) which attaches to and drives the Cam Shaft can crack or break. On rare occasions the Camshaft # 21F-3 ( 1031950 )will break at one end. Also, rare is a cracked Skipper Wheel # 14F-6 ( 1031740 ). Close examination of both sides of the Skipper Wheel is required to detect this failure.
And last, but not least, you can have a gear post break in the housing body it's self. The "Empty 440 Case" # 90F ( 420N66 ) is NO LONGER available ( only the 440i version Backplate, but it can NOT be used with older 440 parts ),
So it is simpler and prudent to replace the Complete Timer Assembly ( with the 440IHV ) at this point.
A complete replacement is also prudent if the unit is over 20 years old.
NOTE: We only have a few of these ( 440 ) left, and we recommend using the NEW version = 460TC as a replacement.

Download Autotrol Manuals from Manufacturer's website here:
Pentair GE Osmonics Autotrol 255 Service Manual 440 / 460
Pentair GE Osmonics Autotrol Performa 263, 268 Service Manual 400 series timer

24NC ( K-5 Less 400 series Timer Assembly), 255 upper valve body no timer 24NC ( K-5 Less 700 series Timer Assembly), no Logix controller, motor, optical sensor, or camshaft 255 LOGIX Rebuild Kit Valve Parts 255LOGIXRBK
24NC LOGIX ( K-5 Less 700 series Timer Assembly)
Usually Ships in 1 to 2 Business Days
Your Price: $179.00
Autotrol 255 Upper Valve Body Replacement without Timer Assembly.
Includes new style cover, which will require slight modification ( cut a little off ) when used with tank adapters that have the 36F Air Check ( pre-1994 models of 155 ).
Autotrol 255 Upper Valve Body Replacement without Timer Assembly ( Newer LOGIX 740, 742, 760, 762 ) .
It would be the PN 1244650 ( valve body ) and 1235340 ( top plate for Logix ) and it would include all Valve Body flow controls and Valve Disc installed / included. Just slide your old 700 series timer, motor,optical sensor and camshaft into place.
New LOGIX controlled 255 Valves ( not 440, 460i ) bodies can be rebuilt with these parts that go into the Autotrol 255 Valve, plus o-rings to tank adapter.
Rebuild Kit for Autotrol 255 Valve Body 255 Upper Valve Module w/Logix 740 Timer Assembly 255 Upper Valve Module w/Timer Assembly
All the parts that go into the Autotrol 255 Valve Body, plus orings to tank adapter. Autotrol 255 Upper Valve Module with 740 LOGIX Timer Assembly,12 volt transformer, camshaft, cover and Oring kit.

Fits all Autotrol 255 and some late model 155 Series Tank Adapters ( old style 155 Air Check, 36F, will hit new top plate and therefore CAN NOT be installed on your tank adapter ).
Autotrol 255 Upper Valve Module with 460TC Timer Assembly, transformer, camshaft, cover and Oring kit.
Fits all Autotrol 155 and 255 Series Tank Adapters.
This is not the complete valve, just the upper valve body and timer assembly.
440 Replacement Timer Assembly 440i HV w/Cord 440i HV Back Plate 460TC Replacement Timer Assembly for 440 series
Complete 440i for 120 volt 60 hz installations - Obsolete
No longer manufactured since Summer 2011
440i ( 1001690 ) and 440iHV ( 1001691 ) Back Plate
Bare Housing Back Plate Only.
Obsolete Item.
Timer Assembly can be replaced with the complete new 460TC we sell.
It will fit on all Autotrol 155, 163, 168, and most 255, 263, and 268 valves.

460TC Replacement 7 DAY Timer Assembly for 440 series, with 12 volt 60 Hz AC Transformer

Upgrade Kit 255/740 Logix Electronic replacing 440i series timer Backwash Control Plug 25F Ball for Flow Control Autotrol  - Old  4F , New 1030502
Backwash Control Plug 25F
Your Price: $9.95
Upgrade Kit 255/740 Logix Electronic replacing 440i and 440iHV series timer Backwash Control - Comes with Orings ( 2F and 3F ) installed.
Please select tank diameter.
Note: Your old Back Wash should have a small number on it that matches your resin tank diameter.

Rubber Ball - Used to regulate flow behind backwash plug and brine control dial.
Old part number 4F, and newer part number 1030502

Brine Control Dial 3-19 lbs. 1F-19 or 1034263 Brine Refill Plug - Logix Backwash Valves PN 1030334 Brine Refill Controller 0.33 gpm PN 1243510
Replacement Brine Control Dial for Autotrol, 3 lbs. - 19 lbs. range.
This is the replacement for both old and new style Brine Controls.
Old part # 1F-19, New part # 1032996 or 1034263
Comes complete with the 2 orings.
PLUGGED - no refill Brine Refill Plug - Logix Backwash Valves PN 1030334 Brine Refill Controller 0.33 gpm PN 1243510
Camshaft Out Put Connector Autotrol 21E or 1031496 Flapper Valve Disc Set 255 Autotrol GE Osmonics 1000250 Gear  Tripper Arm Assembly 99F
Gear Tripper Arm Assembly 99F
Your Price: $14.95
Now Obsolete Part, NONE IN STOCK
21E Output Connector used to connect to CamShaft on the 440 & 460 Timer Assembly.
Used on all 155, 163, 168, 255 timer assemblies. Part Number 21E or 1031496.
Newer Version used in the 440i, 460TC and 460i is slightly different one, AP1001833,
and can be used as a replacement ( shave off "arrow" on the AP1001833, and no C-clip used, but it will still "stay" in place when 440 is re-assembled to provide turning of the Camshaft ).

Recommendation = Complete timer replacement option is the AP460TC.
Valve Disc Set for the Autotrol 255, PN 1000250.
Autotrol ( GE Osmonics ) 255 Valves have been in use since late 1995.
It replaced the Autotrol 155, which was made from 1970 until late 1995.

99F Tripper Arm and Gear for Autotrol 440 and 440i Timer Assemblies.

Gear - # 7 Black 420A43 - 1031554 Gear - # 8 Black 420A44 - 1030844 Gear Tripper Arm 6 Day REVISED PN 3007499
Gear - # 7 Black 420A43 - 1031554
Our Price: $4.99
Gear - # 8 Black 420A44 - 1030844
Your Price: $3.99
Black Drive Gear # 7, 420A43.
This gear drives the Tripper Arm Gear ( 99F ).

Black Drive Gear # 8 .
This Gear Drives the large Red or Black Output Knob Gear.

Gear Tripper Arm 6 Day REVISED PN 3007499
Injector Cap,  Autotrol  1000218 1000269 Injector Screen & Cap Large Injectors For Autotrol Valves - 28F
Injector Cap, Autotrol 1000218 1000269
Your Price: $3.99
Injector Screen & Cap Large
Your Price: $4.95
Injectors For Autotrol Valves - 28F
Your Price: $8.95
Injector Cap ( 1000218 or 1000269 ), Newer 255, and 268 Valves.
Also, part 25D for old 168FA Valve.
Injector Screen & Cap 255, and 268 Autotrol Valves, and Magnum Valves ( Pilot Filter Screen ).
PN 1000226 Includes Cap, Screen and o-ring PN 2F or PN 1010110
Injectors For Autotrol Valves w/Orings ( 26F & 27F ) included.
White AA = 1032970
Blue BB = 1032971
Red CC = 1032972
Green DD = 1030272
Manual for Autotrol 255 Softener O-ring - Backwash Plug or Cap Old PN 2F new PN 1010110 Oring Kit K-7 1001404 Tank Adapter to Valve Body
Manual for Autotrol 255 Softener
Your Price: $10.00
Manual for Autotrol 255 Softener with 440i Timer Large O-ring used on Backwash Plug,Brine Control Dial, and the larger Injector Cap and Injector screen cap ( models 255 and 268 ) on Autotrol Valves.
Part # 2F or 1010110
Valve Body to Tank Adapter O-rings
32F,(4)35F,& 37F
Includes small tube of silicone lubricant
Silicone 1 Gram Tube Lubricant for O-rings Six Day Skipper Wheel, 14F6, 1031740 Skipper Wheel 7 Day
Six Day Skipper Wheel 14F-6 or 1031740
Your Price: $14.95

One gram of food grade silicone for use with o-rings, gaskets and seals.
Enough to lubricate about a dozen or more o-rings and seals.
These tubes come from one of the leading valve manufacturers.

Six Day Skipper Wheel

Seven Day Skipper Wheel ( 14F-7 or 1031742 ) used on Autotrol 440 and 440i Timers
OBSOLETE part - None as of May 2019.
Video Autotrol  155 and 255 Valves
Video Autotrol 155 and 255 Valves DVD
Your Price: $29.00
Common repair and maintenance for Autotrol 155 ( 1550-TC ) AND 255 Valve with 440 and 460 Controls is shown on this Video.
Now together on ONE DVD.