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Rebuilding the Autotrol 155 ( 1550-TC ) 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 # 155A152 ) 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 ) 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 ) 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 11 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.

You can reference this Youtube Video

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 11 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.

Autotrol 155 ( 1550-TC ) Valve Leaks - How to solve them
Autotrol 155 Valve Body Rebuild Kit:

1) Set of Flapper Valve Discs part # 155A152
1) Injector part # 28F- AA, BB, or CC ( based on tank diameter )
1) Brine Control part # 1F-19
1) Backwash Plug part # 25F- # 7 - 14 ( based on tank diameter )
2) Flow Control Balls part # 4F
1) Tank Adapter O-rings ( 32F,(4)35F,37F ) part # 150A129
1) Silicone Lubricant 1 gram

NOTE - Does NOT include the
Injector Screen & Cap part # 7F, or the 8F-BB Injector Cap as these are obsolete items we no longer have.. and not in this rebuild kit.

A much easier solution is to purchase the Upper Valve Body ( comes with all new internal parts ),
either with a new 460TC timer and Camshaft as the K-5
or just the complete upper valve body as the 24NC.

Not only does this save a lot of work, it upgrades your valve body to the new 255 design. The flow rate is higher and some of the parts are beefed up to last longer than they did on the 155 version.

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: There are no 440 Timers left, and we recommend using the NEW version = 460TC as a replacement.

Rebuild Kit for Autotrol 155 Valve Body 24NC ( K-5 Less 400 series Timer Assembly), 255 upper valve body no timer 255 Upper Valve Module w/Timer Assembly
Some of the parts that go into the Autotrol 155 Valve Body, plus o-rings to tank adapter. 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 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 460TC Replacement Timer Assembly for 440 series Backwash Control Plug 25F
Backwash Control Plug 25F
Your Price: $9.95
Complete 440i for 120 volt 60 hz installations - Obsolete
No longer manufactured since Summer 2011

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

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.
Ball for Flow Control Autotrol  - Old  4F , New 1030502 Brine Control Dial 3-19 lbs. 1F-19 or 1034263 Camshaft Out Put Connector Autotrol 21E or 1031496

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

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.
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.
Flapper Valve Disc Set 155 and 168 Series 155A152, 1033013 Gear  Tripper Arm Assembly 99F Gear - # 7 Black 420A43 - 1031554
Gear Tripper Arm Assembly 99F
Your Price: $14.95
Gear - # 7 Black 420A43 - 1031554
Our Price: $4.99
Flapper Valve Disc Set, # 155A152 for 155, 150, 160, 163, and 168 Series Valves.
Osmonics newer part # 1033013.
Some older manuals have part # 165N109 as the part number for this SET.

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

Black Drive Gear # 7, 420A43.
This gear drives the Tripper Arm Gear ( 99F ).
Gear - # 8 Black 420A44 - 1030844 Gear - Red or Black Output 440 Timer - 420B52, 1001583 Injector Cap 8F-BB
Gear - # 8 Black 420A44 - 1030844
Your Price: $3.99

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

Red Output Gear for 440 and 440i Timer assembly used on some Autotrol 155, 1550-TC, 163, 168, 255, 263, 268.
Very old PN was 420B52.
NEW COLOR IS BLACK for this Gear ( newer PN in some manuals 1001583 ).
Identical to older Red version.
"Old Style" Injector Cap. Comes with new oring. Used on all Autotrol valves 155 which were made up until 1996.
And all Autotrol 163,168,and 169 which were made up until 2000.
Newest PN = 1032974
Injector Screen Cap 7F Injectors For Autotrol Valves - 28F Manual for Autotrol 155 ( 1550-TC )
Injectors For Autotrol Valves - 28F
Your Price: $8.95
Manual for Autotrol 155 ( 1550-TC )
Your Price: $10.00

Injector Screen and Cap with o-ring.
Used in older Autotrol Valve Models 155, 163, and 168.
Obsolete part = NONE Remaining as of July 2017

Injectors For Autotrol Valves w/Orings ( 26F & 27F ) included.
White AA = 1032970
Blue BB = 1032971
Red CC = 1032972
Green DD = 1030272
Installation, Operation & Maintenance Manual for the Series 155 ( which is the same as 1550-TC ). It is 16 pages. Copyright 10/1991.
O-ring - Backwash Plug or Cap Old PN 2F new PN 1010110 Oring Kit K-7 1001404 Tank Adapter to Valve Body Silicone 1 Gram Tube Lubricant for O-rings
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

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.

Skipper Wheel 7 Day
Seven Day Skipper Wheel ( 14F-7 or 1031742 ) used on Autotrol 440 and 440i Timers
OBSOLETE part - None as of May 2019.