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Instructions for Replacing the Pressure Chamber

Applicable to the following sprayer models:

Step-by-step how to:

  1. Unscrew both nuts that hold the diaphragm crank to the pump handle. Remove both nuts and pressure washers. Lift crank away from the two screws. It is not necessary to remove the aluminum crank from the diaphragm.
  2. Remove the clip that holds the pump handle in the spray pack.
  3. Slide pump handle slowly to the left, then slip out the screws from the pump handle completely. Complete sliding of handle to the left and remove completely from spray pack. Be sure not to lose the nylon washers.
  4. Remove the hose from the sprayer by removing the 90° fitting and hose clamp. The diaphragm is now exposed and can be removed.
  5. Place a large rubber band over the circular metal ring that holds the diaphragm together or use a pair of gloves to grip the pump module. Turn the complete diaphragm counter-clockwise until it is completely unscrewed from the spray pack. Set the pump module aside.
  6. Once the diaphragm has been removed, you will notice a small mark or plastic protrusion, both on the diaphragm and on the spray pack. Look for the marks. These marks are placed here for aligning. When the new diaphragm is put in, these marks must align for proper functioning.
  7. With a screw driver, loosen the large metal clamp that holds the pressure chamber in place. Remove the clamp completely. Stand the sprayer up right and place your hand on top of the pressure chamber. Press down and move from side to side until the pressure chamber is completely out of the unit.
  8. Place the pressure chamber into the tank, and push up into the tank until it is completely into the sprayer. You will notice that there is an aligning notch cut out on the chamber and a protrusion on the tank to make alignment easy. Once the chamber is all the way in replace the retention clamp and tighten.
  9. You are now ready to replace the pump module. Locate the aligning marks on the spray pack and the diaphragm. Please oil on the O-rings to prevent damage and to make threading easier. Place the diaphragm into position and turn clockwise. Turn until the large O-ring on the diaphragm is no longer visible. Make sure the markings on the diaphragm and the spray pack are aligned.
  10. Replace the pump handle into the spray pack. Make sure the nylon washers are in place. Slide the handle in slowly and immediately put screws through the screw holes, one at a time.
  11. Once the screws are in place, push the pump handle the rest of the way. You may now put the pin in place.
  12. Connect the hose by inserting the 90° fitting into its original position and tighten the hose clamp.
  13. Place screws through the holes on the aluminum crank. Replace the pressure washer and nut. Tighten firmly.
  14. Your sprayer is ready to use.

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