Refill Instructions
HP 51604a

1. Remove the plastic ball from the filling hole using an eyelet screw. Save ball to re-seal hole after refilling.
2. Assemble the syringe and filling needle and fill with 7ml of ink.
3. Hold the cartridge upright and insert the filling needle into the filling hole. Do not insert fully - be careful not to pierce the rubber ink sack.
4. Slowly inject the ink into the cartridge.
5. Withdraw the syringe and replace the sealing ball. Insert firmly to prevent leakage.
6. Mount the cartridge and run a priming cycle as per printer instructions.

Note: Here is what one customer wrote about refilling this cartridge.
My cartridge looked the same as the one in the diagram except there was no fill hole. What I had to do was use a small screwdriver to pry the top of the cartridge off, exposing the foam insert. I simply let the ink drip slowly until it was saturated and replaced the cover.

Note: Empty cartridges should be refilled immediately.

A Refill Kit should include Ink plus the following: One - 10cc Syringe w/ blunt needle Eyelet screw Aluminum Tape

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