Replacing a grease gun cartridge takes five minutes and requires only the cartridge itself

A grease gun cartridge is the sealed tube of lubricant that fits inside your grease gun. When it empties, you remove the old one and slide a new one in — no tools needed beyond what comes with the gun. The process is the same whether you own a caulk-style gun, a pistol-grip gun, or a lever-action model, though the exact steps differ slightly by design.

Most cartridges are standard 10-ounce tubes that cost between $3 and $8 each, depending on the grease type. You can buy them at any hardware store, auto parts retailer, or online. The key is matching the cartridge to your gun's barrel diameter — usually 1.3 inches or 1.5 inches — and knowing whether your gun uses a plunger rod or a follower plate to push the grease out.

Key Takeaways

  • Empty the gun completely by pulling the trigger until no grease comes out, then unscrew or unclip the barrel to access the old cartridge.
  • Pull the plunger rod all the way back before removing the cartridge, or the rod will jam inside the barrel.
  • Slide the new cartridge in nose-first, then push the plunger rod forward until it seats firmly against the cartridge base.
  • Cut the foil seal off the cartridge tip with a utility knife before screwing the barrel back on and priming the gun.
  • The first few pumps will push air out instead of grease — this is normal and takes three to five trigger pulls to clear.

Empty the gun and open the barrel

Before you remove anything, pump the trigger until no grease comes out. This relieves pressure inside the barrel and makes the cartridge easier to remove. If you skip this step, the cartridge may stick or grease may spray when you open the gun.

Locate the barrel connection point. On a caulk-style gun, the barrel screws onto the handle — turn it counterclockwise by hand until it comes free. On a pistol-grip or lever-action gun, look for a clip or latch near the back of the barrel; press or slide it to release the barrel from the frame. Some models have a threaded collar instead of a clip — turn it counterclockwise to loosen.

Pull the plunger rod all the way back

The plunger rod is the long metal shaft that runs through the center of the barrel and pushes the cartridge forward. Before you remove the old cartridge, pull this rod all the way toward you — usually by pulling the trigger handle or lever to its rearmost position. On a caulk gun, you may need to unscrew the handle slightly to access the rod.

This step is critical. If the rod is still pressed forward when you try to slide the cartridge out, it will jam inside the barrel and you will have to disassemble the gun further to free it. Once the rod is fully retracted, you should be able to slide the old cartridge straight out of the barrel with your fingers.

Insert the new cartridge and reseat the plunger

Slide the new cartridge into the barrel nose-first — the pointed end goes in first. Push it all the way to the front until it stops. The cartridge should sit flush with the barrel opening; if it sticks out, you may have the wrong size or the barrel may be damaged.

Now push the plunger rod forward until it makes firm contact with the base of the cartridge. You should feel resistance — the rod is now pressing against the cartridge and ready to push grease out. Do not force it; if it does not move smoothly, the cartridge may be misaligned. Pull it out, check that the barrel is clean, and try again.

Cut the foil seal and reattach the barrel

Every new cartridge has a foil or plastic seal covering the tip. Use a utility knife or the small blade on a multi-tool to cut this seal away — cut at an angle, not straight across, to avoid damaging the cartridge nozzle. Some guns have a built-in cutter on the barrel cap; if yours does, you can use that instead.

Screw or clip the barrel back onto the gun frame. If it screws, turn clockwise until snug — do not over-tighten, as this can crack the barrel. If it clips, push the barrel forward until you hear or feel the latch click into place. The gun is now ready to use.

Prime the gun to remove air

The first few pumps will push air out of the barrel instead of grease. This is normal. Pull the trigger or work the lever three to five times until grease appears at the nozzle. This process is called priming. Once grease comes out, the gun is ready to use on your equipment.

If grease does not appear after ten pumps, the cartridge may not be seated properly or the nozzle seal may not have been cut completely. Stop, unscrew the barrel, and check that the cartridge is pushed all the way forward and the plunger rod is touching it firmly. Reattach and try again.

Choosing the right replacement cartridge

Cartridges come in different sizes and grease types. The most common size is 10 ounces, which fits standard caulk-style and pistol-grip guns. Some heavy-duty guns use 14-ounce cartridges, and a few older models use smaller 3-ounce tubes. Check your gun's manual or look at the barrel — it usually says the cartridge size.

Grease types matter too. General-purpose lithium grease works for most household and light equipment use. If you are lubricating a car, check the owner's manual for the recommended type — some vehicles need synthetic grease or grease with specific additives. Using the wrong type can damage seals or reduce equipment life. When in doubt, ask the parts counter staff what grease the equipment manufacturer recommends.

Frequently Asked Questions

What if the plunger rod is stuck and won't pull back?

The rod may be frozen by dried grease. Spray penetrating oil around the rod where it enters the barrel and let it soak for 15 minutes. Then gently work the trigger or lever back and forth — do not force it. If it still will not move, the gun may need disassembly by someone familiar with the model.

Can I reuse an old cartridge?

No. Cartridges are sealed tubes designed for single use. Once empty, they cannot be refilled safely. Attempting to refill one risks leaks and uneven pressure. Buy a new cartridge instead — they are inexpensive and widely available.

Why is grease leaking from the barrel connection?

The barrel may not be screwed on tightly enough, or the seal between barrel and frame may be worn. Unscrew the barrel, wipe the threads clean with a dry cloth, and screw it back on firmly. If it still leaks, the seal may need replacement — check your gun's manual for the part number.

How do I know if my gun uses a plunger rod or a follower plate?

Pull the trigger or lever all the way back and look inside the barrel opening. If you see a long metal rod, you have a plunger rod gun. If you see a flat metal disc, you have a follower plate gun. Both work the same way — pull the rod or plate back before removing the cartridge.

What size cartridge does my gun take?

Check the barrel itself — most guns have the cartridge size printed or stamped on the side. If not, look at the manual or measure the barrel opening with a ruler. Standard sizes are 10 ounces (most common), 14 ounces (heavy-duty), and 3 ounces (specialty). The barrel opening diameter is usually 1.3 or 1.5 inches.