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Refill Instructions for HP 4-cartridge systems

  • HP #940 and #940XL Cartridges
  • HP #88 and #88XL Cartridges
  • HP #10 Cartridges
  • HP #11 Cartridges
  • HP #12 Cartridges
  • HP C4841A, C4842A, C4843A, C4844A, C9396A Cartridges
  • HP C4804A, C4805A, C4806A, C4836AN, C4837AN, C4838AN Cartridges
  • HP C4902AN, C4903AN, C4904AN, C4905AN, C4906AN, C4907AN, C4908AN, C4909AN Cartridges

HP Business Inkjet Series Printers

Updated December 1, 2010


These cartridges are virtually identical and refill the same, with the only differences being the size of the cartridges. The ink in these cartridges is retained because the cartridge develops a slight pressure. These cartridges are plastic boxes which contain ink bags. While some of these cartridges fail after only 3 or 4 refills, most can be filled 20 or more times.

Click here for video instructions.

#940 and #940XL cartridges only: To reset this cartridge's chip, hold down the reset button for 1 to 2 seconds.

#940 and #940XL must use the inkset indicated. Mixing other inks into 940 and 940XL cartridges will cause serious damage to the printing system as the ink coagulates.

10, 11, 12, 13, 88, 88XL Inks

  • Black: WJ-1021
  • Cyan: WJ-291
  • Magenta: WJ-688
  • Yellow: WJ-757

940, 940XL Inks

  • Black: WJ-1168
  • Cyan: WJ-2121
  • Magenta: WJ-6172
  • Yellow: WJ-7050

Built-in Chip

These cartridges have a built-in electronic chip. Don't Panic! This chip contains a serial number for the cartridge and an expiration date. The expiration date is typically placed about 2 years or so from the date of manufacture, and is also printed on either the box or the cartridge. The way the printer treats this expiration date doesn't depend upon whether or not you have refilled the cartridge. If you refill the cartridge twenty times - or never refill the cartridge - the cartridge will become inoperable after the expiration date. However, this is not such a big deal, since two years or so on a cartridge often means you will have refilled the cartridge a dozen times or more.

If this appears to be a limitation to you, we suggest that you dedicate a computer to hosting the printer and set the date on the computer to March 1997 or some such similar date. This way, the printer will never realize that the expiration date has come and gone. (Of course, having the wrong date may cause other problems in other software you may be running....)


Read the entire Instructions below before beginning.

Step 1) Put the cartridge on some paper towels in an area where you can tolerate a spill such as a sink. Be sure that you are wearing old clothes, since the first time you fill the cartridge, you will probably get some ink on your clothes and hands. You may wish to wear rubber gloves if you don't want to stain your hands. We also don't recommend refilling as a family project -- it's amazing what a three-year-old can do with a pint bottle of highly concentrated ink! Not to mention what Fido or MS. Kitty can do by bumping either their beloved person or the bottle. See our General Information for more details.

Step 2) Look at the cartridge. Near the bottom of the cartridge you will see a horizontal break line in the plastic where the two parts of the cartridge snap together.

Step 3) Using a sharp knife or scissor blade, cut the label on the front of the cartridge along the line where the two parts of the cartridge come together.

Step 4) Using a knife,screwdriver, or just your hands pry the cartridge open along the line. Let it hang by the backside label.

Step 5) The exit port is the point where the ink comes out of the cartridge. It has an obvious stem. Place this stem to your right.

Step 6) You will also see a rubber oval-shaped bulb. To the left of this bulb is the fill hole. You will see a small ball in this hole. Stick a pin or the end of a sharp knife into this ball and pry or lift it out of the hole. (Saundra recommends a sharp steak knife. (*** Don't stab or cut yourself!***) Don't lose the ball!

Step 7) Fill your syringe bottle with the appropriate ink. You'll need about 30 ml (1 full syringe bottle) for the regular cartridges, about 75 ml (2 1/2 syringe bottles) for the high capacity black cartridge.

Step 8) Insert the needle 1/4 to 1/2 inch (5-10mm) into the fill hole. Be careful not to puncture the bag, especially if you have a sharp needle.

Step 9) Inject the ink into the opening.

Step 10) Tilt the bag so that the opening is at the top. This will let the air bubble up and out.

Step 11) Using the syringe, suction about 1 ml (1/4 teaspoon) of ink and air frothy mixture out of the top of the bag.

Step 12) Inspect the ball. If it has been damaged, you should use a new ball or the damage may cause a slight leak. (We have additional balls for sale.)

Step 13) Replace the ball in the cartridge. Saundra says, "The tip of a retracted ball-point pen is ideal for this."

Step 14) Turn the cartridge upside down (stem down) and gently squeeze to check for leaks.

If you see a leak there are three possible problems.

1. The bag inside the cartridge has bursted or is punctured. There is no fix for this: the cartridge is dead.

2. While refilling you allowed ink to escape and get on the white collar surrounding the exit port, bulb and fill hole. The ink has now leaked between the bag and the sides of the cartridge. Even though this is usually only a small amount of ink it will act like you poured an entire pint in there! The solution is to remove the bag. Please do this over the sink. As you are looking at the cartridge you will notice that the sides are long ovals. Hook your thumbs inside the ovals and pull as if though you are going to pull the cartridge apart. You will see two plastic tabs. Release one and then the other. Using the bulb frame as a gripping point, pull straight up and lift the bag. This will be messy. Rinse the outside of the bag and the inside of the cartridge shell. Try not to get water on the copper chip while you are working. Using an old towel or a paper towel, dry off the bag and dry out the inside of the cartridge.

3. You have not pushed the ball into the hole securely. Push it in again and wipe up the excess ink. Squeeze the cartridge to make sure you have it sealed tightly before putting it back in the printer.

If there are no leaks insert your cartridge into the printer and print.

The light on your printer warning you that the ink is low will remain ON. This is normal. Do not panic: just see if it prints.


If the Printer says you are still out of ink and Refuses to print:

The most likely cause is that you have air in the bulb at the bottom of the cartridge. The next few steps are to remove air that may be causing the printer to think that it is out of ink.

Step 1) Tilt the bag so that the exit port is at the bottom facing downward toward your sink.

Step 2) Insert syringe tip into exit port to hold open the spring loaded valve.

Step 3) Press cartridge bulb and HOLD. Do not release until step 6 is complete. This will be messy as ink and air should be released, so work over a sink!

Step 4) Remove syringe tip from exit port.

Step 5) Now release bulb.

Step 6) Wait 5 seconds or so until chamber under bulb is full.

Step 7) If you have excessive air Steps 1 to 6 may have to be repeated 3 times before your cartridge will operate properly.

Typical Problems

The printer says the cartridge has expired.
It has. Either get a new cartridge or reset the date on your computer to a year ago.

The printer does not recognize the existence of the cartridge, or says the cartridge is bad.
Check the tiny copper contacts to make sure that they are clean and making contact with the printer. You may need to clean them with a tissue dampened in warm water, or bend the contacts very slightly outward.

The printer says you are out of ink -- yet you have a full cartridge.
Begin at Trouble-Shooting and follow the first procedure, steps 1-6.

All of the lights on the printer are on.
There are a couple of possibilities, none of which are directly related to the ink.
  • You have a paper jam. Once, we had a tiny piece of paper less than 1 inch square which we finally found was causing the problem.
  • Your printer has lost its mind. Unplug the printer, completely shut down the computer, and restart both to completely clear the printer's mind.
The cartridge won't print and printhead cleaning routines make the problem worse.
If air is present in the chamber below the bulb, then ink will not be pumped successfully. We need to remove the air.
  1. Using a hypodermic needle or your syringe bottle, insert the needle into the ink exit port and remove about 3 ml (3/4 teaspoon) of ink by suction.
  2. While the needle is still in the ink exit port, squeeze the bulb.
  3. Remove the needle.
  4. Now release the bulb. This should have removed the air.

To Clean the Printhead

If the cartridge initially prints with too much or too little ink, it may be necessary to clean the printhead.
  1. Do not clean the printhead unless you get poor print quality, or no printing.
  2. Locate the HP Printer Utilities folder on your computer and find the Printhead Cleaning button. Run the cleaning software and check for improvement in the printout. You may need to run this software a few times.
  3. Follow the cleaning directions in the printer manual.

To Clean Your Sink

The ink is water-soluble. Use plenty of soap and warm water. You may also need to use Comet or a similar cleaner if the stains persist.

To Clean Your Hands

On hands, the best substance to use is Ink Be GoneTM, a specially developed hand cleaner available from ACSI Bulk Inks. (To place an order, Click Here.)

To Place An Ink Order

You can telephone us at 1-888-728-2465 (USA Tollfree) or 1+740-374-9949. You can also Order Online or by other ways including by Fax, or by Postal Mail, or by EMAIL.
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