Remove the four screws securing the pump head. These screws are located on the back of the metering pump.
After loosening the pump head, before removing it, adjust the stroke length to the 0% position. This ensures sufficient pressure on the solenoid shaft to maintain a secure connection, allowing you to unscrew the diaphragm.
Pull the hydraulic end outwards to disengage the screw from the socket. Grasp the liquid end and rotate counterclockwise. With slight resistance, you can unscrew the diaphragm.
Once the diaphragm is removed, inspect the metering pump's safety diaphragm to ensure it is intact and undamaged. Install the new diaphragm, rotating the backplate and diaphragm clockwise until they are flush. Adjust the backplate so that the drain hole is at the bottom of the pump.
After the diaphragm is installed and the backplate drain hole is in a vertical position, install the pump head. Ensure the suction valve is aligned with the drain hole and the screws on the hydraulic end are aligned with the corresponding four holes.
Rotate to the 100% stroke length position. This will align the entire assembly with the backplate drain hole at the bottom of the pump. Adjust the hydraulic end and diaphragm to the appropriate positions while the pump is running.
Once the hydraulic end and backplate are in the correct positions, tighten the four bolts diagonally until they are properly tightened. Apply even force when performing this operation.
