Refill HP 934XL and HP 934XL inkjet cartridges by combining dripping and using a fill port

The XL cartridges HP 934 and HP 935 have two tank sections inside whereas the standard yield cartridges have one section only. The tank section located above the ink port is filled with a sponge material (1). This sponge is responsible for holding the ink inside the cartridge. The tank in the rear section (2) does not have that sponge material. Both tanks are connectd to each other by an opening in the deviding wall (3) between these two chambers. By dripping ink You can fill the sponge section only, the rear tank stays empty.

Luckily it is not necessary to do any drilling as there is a fill port that is easy to open for filling the rear tank too. To access that fill port it is necessary to remove the label from the upper side of the cartridge.

Fill the sponge section first by dripping ink on the sponge that You can see in the ink port of Your empty HP 934 Xl or HP 935 XL. The sponge is saturated with refill ink if it does not absorb more of the ink dripped onto the ink port. Close the ink port (4) and turn the cartridge to position it this port pointing downwards. I the upper wall of the rear tank there is a fill port that is closed by a small plastic ball. To open this fill port You can punch this ball into the cartridge (5). Now You can fill the rear tank by using a syringe or pipette.
The aim is to come as close as possible to the original full weight of the HP 934 XL or HP 935 XL cartridge.

[] HP 935 XL Tintenauslass verschließen Tankverschluß einstoßen

Cartridge weights FULL
HP 934 XL Black 67g
HP 935 XL Cyan, Magenta, Yellow 28g

PLease close the fill port when the rear tank is filled with ink too. You can use a suitable rubber plug or You can work with hot glue. Both solutions provide the opportunity to use this fill port again for future fillings.
Pay attention to the air port and the air duct, whioch are located above the sponge section, on the upper side. The must be free of ink or any other blockade to ensure that the ink is flowing sufficiently towards the print head during printing.