dosatron D14MZ5AFII User manual

800-523-8499 • 727-443-5404
Extend the Life of Your Dosatron
REBUILD KIT
D14MZ5AFII
Part #: MKD14MZ5AF
Kit includes:
Part 1: Piston Kit
Upper ange
Lower ange
Omega spring
Connecting rod
Push rod seal
Part 2: Seal Kit
Injection sleeve o-ring
Injection stem o-ring
Check valve assembly
Plunger seal

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This kit is for the Dosatron D14MZ5AFII and consists of two parts:
Congratulations on purchasing your
Dosatron Rebuild Kit.
Part #: MKD14MZ5AF
Part 1 - Piston Kit Contents:
PDI651 - Omega Spring
PDI649 - Connecting Rod
PDI648 - Push Rod Seal
PDI643 - Upper Flange
PDI644 - Lower Flange
• Part 1 - Piston Kit
Part 2 - Seal Kit Contents:
PJDI117 - Check Valve Assembly
JDI122 - Injection Stem O-Ring
JDI100 - Injection Sleeve O-Ring
JDI121 - Plunger Seal
• Part 2 - Seal Kit
Remember to wear proper protection when performing maintenance
such as gloves, eyewear, and apron.

800-523-8499 • 727-443-5404
MKD14MZ5AF
Part 1: Piston Kit Instructions
Begin by removing the piston
from your Dosatron injector.
Unscrew and remove the bell
housing (you may use a
universal strap wrench), pulling
the piston out of the body. Set
the bell housing and body aside.
Remove the plunger by twisting
a quarter turn counter clockwise
and set aside.
In order to remove the top or
larger diameter ange, locate the
small notch inside the black
piston shell. This is where a
tooth, on the inside of the
ange, locks it into place.
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You will need to apply pressure
to the ange on either side of
the notch as you twist the ange
counter clockwise. It may be
a snug t. Lift to remove and
discard.
Flip the piston upside down
and follow steps 3 and 4 to
remove the lower or smaller
diameter ange.
To remove the motor and valve
support assembly from the piston
shell, you will need a at head
screwdriver. Using the
screwdriver, remove the upper
valves from the guide. The
valves look like golf tees and
will drop down and out of the
piston shell. Set them aside.
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Grasp the top of the white plastic
parts of the mechanism and lift
straight up.
You now have two
subassemblies – the push rod
on the left and the valve support
frame on the right.
In order to disassemble the push
rod, remove the connecting rod
off the Omega spring.
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Twist to remove the Omega
spring out of the push rod.
Install the new Omega Spring
(Part #: PDI651) by carefully
pushing the Omega spring into
the push rod.
Slide the other end of the Omega
spring into the new Connecting
Rod (Part #: PDI649). The key
to this step is to make sure the
curved top of the push rod faces
in the same direction as the
Omega spring.
Replace the Push Rod Seal
(Part #: PDI648). Remove by
grasping and turning counter
clockwise. Carefully slide the
new push rod seal onto the
push rod as far as it will go and
twist a quarter turn clockwise
to lock.
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Install the new Upper Flange
(Part #: PDI643) by locating the
small tooth on the inner diameter
of the ange.
Now locate the notch on the
piston shell.
Be careful not to install the
ange upside down.
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Align the tooth with the shell and
press down and twist a quarter
turn clockwise to lock. If it is
difcult to twist or if the ange
lifts up easily, just remove the
ange, realign and try again.
Install the new Lower Flange
(Part #: PDI644) the same way.
Before reinstalling the push rod
and valve support assembly, look
inside the piston shell. You will
notice four holes in a line and a
single hole on the other side.
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Notice how the valve support
frame aligns on the side with the
four holes, making sure it goes
into the grooves.
To demonstrate the alignment
of the push rod assembly, the
curved top would face inward,
inserting the push rod into the
single hole. This is where
the connecting rod sits in
the piston.
The key is to make sure the
white connecting rod drops
into the notches inside the
piston shell.
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Now to insert both the valve
support frame and the push rod
into the piston shell, use your
index nger to push on the
spring. This will set everything
into place and you will hear
a click. If the parts aren’t
tting together, just lift both
subassemblies out and try again.
Insert the upper valves into the
bottom of the upper area,
snapping them into the valve
support frame.
To test the piston pull the push
rod up and press it down a few
times. It should click in both
directions.
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