DOSATRON®

1. Remove Dosing Stem

Remove the 4 screws (M101) at the base of the unit. Pull the dosing stem straight out to remove it.

Diagram description: Shows the unit base with screws being removed and the dosing stem being pulled out.

2. Remove Check Valve Assembly

Unscrew the suction hose nut (PDI038) and check valve nut (PDI036). Pull out the check valve assembly (PJDI026), noting the orientation of the inner check valve cone with its spring.

Diagram description: Shows unscrewing nuts (PDI038, PDI036) and removing the check valve assembly (PJDI026) with its internal components.

3. Disassemble Stem Components

Unscrew the locking nut (PDI381) and remove the locking ring (P189). Remove the black adjusting sleeve (P167U1) and the metal mounting collar (M079). Push firmly from below to release the inner white stem (PDI583) from the graduated sleeve (P165).

Diagram description: Illustrates unscrewing nuts and rings, removing sleeves and collars, and separating the inner stem from the graduated sleeve.

4. Replace Injection Stem O-ring

Pinch and remove the injection stem o-ring (JDI098) from the white stem (PDI583) and replace it with the new o-ring.

Diagram description: Shows removing and replacing the o-ring (JDI098) on the injection stem (PDI583).

5. Replace Graduated Sleeve O-ring

Pinch to remove and replace the graduated sleeve o-ring (J024) from the graduated sleeve (P165).

Diagram description: Shows removing and replacing the o-ring (J024) on the graduated sleeve (P165).

6. Reassemble Injection Stem

Insert the injection stem (PDI583) into the top of the graduated sleeve (P165). Push firmly down on the injection stem as far as it will go. Ensure the long groove in the injection stem aligns with the tooth inside the graduated sleeve.

Diagram description: Illustrates inserting the stem (PDI583) into the sleeve (P165) and aligning internal grooves.

7. Reattach Sleeves and Locking Ring

Slide the metal mounting collar (M079) over the graduated sleeve (P165) and injection stem (PDI583). Screw the adjusting sleeve back onto the graduated sleeve (P165) enough to expose the locking ring grooves in the lower, threaded area of the injection stem (PDI583). Align the inner teeth on the locking ring (P189) with the exposed grooves on the lower injection stem (PDI583) and slide up the grooves to the base of the adjusting sleeve (P167U1).

Diagram description: Shows sliding on the collar (M079), screwing on the adjusting sleeve, and fitting the locking ring (P189) onto the stem grooves.

8. Reassemble Check Valve and Hose Nut

Screw the locking nut (PDI381) back onto the injection stem assembly. Insert the new check valve assembly (PJDI026), noting the orientation of the inner check valve cone with spring into the exposed injection stem. Screw on the check valve nut (PDI036) and replace the suction hose nut (PDI038).

Diagram description: Shows reattaching the locking nut (PDI381), inserting the check valve assembly (PJDI026), and screwing on the nuts (PDI036, PDI038).

9. Replace Plunger Seal

Pinch the plunger seal to remove it and replace with the new plunger seal (JDI106).

Diagram description: Shows removing and replacing the plunger seal (JDI106).

10. Reinsert Stem Assembly

Align the ratio guide to the front and reinsert the injection stem assembly.

Diagram description: Shows aligning the ratio guide and reinserting the assembled stem.

11. Secure Unit and Hose

Align the metal collar (M079) with the holes in the body. Install the four screws using a #2 Phillips screw driver. Remove suction hose nut (PDI038) and reattach suction hose onto the check valve barb. Reattach suction hose nut (PDI038).

Diagram description: Shows aligning the collar (M079), installing screws, and reattaching the hose.

Important Note: To ensure the hose is air-tight, you may choose to carefully cut the top of the hose before reinserting. ?

1. Remove Lid

Remove the blue lid.

2. Lift Piston

Lift piston from unit.

3. Remove Wishbone Assembly Components

Remove screw (8M003) and wishbone holder (P394) from wishbone valve assembly (MP178). Slide inlet valve out from its secure clip-on wishbone assembly (MP178).

Diagram description: Shows removing screws and holders from the wishbone assembly and sliding out the inlet valve.

4. Remove Shell Screws

Remove the 4 screws from the middle of the shell. The mechanism will drop out.

5. Replace Actuator Springs

Remove the Actuator Springs (M238) and replace them.

Diagram description: Shows removing and replacing the actuator springs (M238).

6. Install Mechanism in Piston Shell

Replace the mechanism into the new Piston Shell (P421). Make sure to tighten screws while holding the mechanism from below to ensure a secure, flush fit against the inside surface of the piston shell (P421).

Diagram description: Illustrates placing the mechanism into the new piston shell (P421) and tightening screws.

7. Reattach Wishbone Assembly

Clip the wishbone assembly (MP178) back into its proper position on top of the inlet valve. Secure the back of the wishbone assembly by installing the wishbone holder (P394) and securing it with screw (8M003).

Diagram description: Shows clipping the wishbone assembly (MP178) back and securing it with the holder (P394) and screw (8M003).