The drive cap assembly contains the drive cap, the main drive gear, drive cap spline, piston rod and
various other parts that should not be dissembled in the field. The only replaceable part on the drive cap
assembly is the 0-ring. Attached to the drive cap assembly is the main piston (down flow or up flow) and
if a regenerant is used, a regenerant piston.
The regenerant piston (the small diameter one behind the main piston) is removed from the main piston
by unsnapping it from its latch. Chemically clean in dilute sodium bisulfite or vinegar or replace the
regenerant piston if needed. To remove the main down flow or up flow piston fully extend the piston
rod and then unsnap the main piston from its latch by pressing on the side with the number. Chemically
clean in dilute sodium bisulfite or vinegar or replace the main piston.
Reattach the main piston to the drive cap assembly. Reattach the regenerant piston (if needed) to the
main piston. Do not lubricate the piston rod, main piston or regenerant piston. Lubricant will adversely
affect the red or clear lip seals. Reinsert the drive cap assembly and piston into the spacer stack
assembly and hand tighten the drive cap assembly. Continue to tighten the drive cap assembly using a
screwdriver as a ratchet until the black o-ring on the spacer stack assembly is no longer visible through
the drain port. Excessive force can break the notches molded into the drive back plate. Make certain
that the main drive gear still turns freely. The exact position of the piston is not important as long as the
main drive gear turns freely.
Reattach the drive assembly to the control valve and connect all plugs. After completing any valve
maintenance, press and hold NEXT and REGEN buttons for 3 seconds or unplug power source jack (black
wire) and plug back in. This resets the electronics and establishes the service piston position. The display
should flash all wording, then flash the soft ware version (e.g. 154) and then reset the valve to the
service position.
spacer stack assembly
To access the spacer slack assembly remove the drive assembly, drive cap assembly and piston. The
spacer stack assembly can be removed easily without tools by using thumb and forefinger. Inspect the
black 0-rings and red or clear lip seals for wear or damage Replace the entire stack if necessary. The
spacer stack assembly has been 100% tested at the factory to insure proper orientation of one way
seals. Do not disassemble the stack.
The spacer stack assembly maybe chemically cleaned (dilute sodium bisulfite or vinegar) or wiped with a
soft cloth.
The spacer stack assembly can be pushed in to the control valve body bore by hand. Since the spacer
stack assembly can be compressed it is easier to use a blunt object (5/8″ to 1-1/8″ in diameter) to push
the center of the assembly into the control valve body. – The assembly is properly seated when at least
four threads are exposed (approximately 5/8″). Do not force the spacer stack assembly in. The control
valve body bore interior can be lubricated with silicone to allow for easy insertion of the entire stack. Do
not use silicone or any other type of lubricant on the red or clear lip seals or the piston.
Reattach the drive cap assembly and piston(s) and the drive assembly.
