To fill a grease gun cartridge, remove the barrel, seat a new tube with the open end first, release the plunger, then prime the grease gun to push out air.
Swapping in a new cartridge shouldn’t leave you with greasy hands or wasted product. This guide shows clear steps, quick priming tricks, and smart cleanup so your fittings get clean, consistent grease every time. You’ll see what each part does, which way the tube goes, and how to purge air on the first try.
What You’ll Need And Why It Matters
Gather a new 14-oz grease cartridge, paper towels or shop rags, nitrile gloves, and a plastic scraper or clean stick. A clean rag saves time later when you seat the coupler on a zerk. Gloves keep grip steady and the barrel clean inside. If your gun has a bleeder screw, keep a small flathead on hand.
Safety And Cleanliness Basics
- Park equipment, kill power, and block any moving parts before greasing.
- Wipe each zerk before and after greasing so grit doesn’t ride in with the grease.
- Keep the cartridge ends clean while you remove the caps; dust in the barrel shows up later as coupler wear.
Grease Gun Parts And What They Do
| Part | What It Does | Notes |
|---|---|---|
| Barrel | Holds the grease cartridge | Keep threads clean so it seats square. |
| Pump Head | Moves grease with each stroke | Air bleeds here on some models. |
| Follower Rod | Pulls the plunger spring back | Locks into a notch for loading. |
| T-Handle | Lets you grip and retract the rod | Pull fully to clear the barrel. |
| Spring & Plunger | Push grease toward the head | Keep the cup straight and clean. |
| Air Bleeder | Vents trapped air | Crack open during priming if fitted. |
| Hose Or Rigid Tube | Delivers grease to the coupler | Use hose for tight spots; tube for control. |
| Coupler | Locks onto the zerk | Click fully on to stop blow-by. |
| Cartridge Cap/Tab | Seals each end of the tube | Remove the plastic cap first; pull the metal tab last. |
How to Fill a Grease Gun Cartridge: Step-By-Step
These steps match common lever and pistol-grip models and mirror how major brands describe cartridge loading. The two keys: point the open end down into the barrel, and prime at the head to clear air.
- Retract and lock the follower rod. Pull the T-handle fully back and set it in the rear notch so the spring stays compressed.
- Unscrew the barrel from the pump head. Turn it off cleanly so you don’t cross-thread on reassembly.
- Pull the empty tube out. If a used cartridge is inside, slide it out and wipe the bore of the barrel.
- Prep the new cartridge. Pop off the plastic cap from the open end. Leave the metal pull-tab on the other end in place for now.
- Insert the cartridge, open end first. Feed the open end down into the barrel until the rim seats at the mouth. This keeps the tabbed end facing the head for easy removal later.
- Remove the metal pull-tab. With the open end already seated in the barrel, pull the tab to uncover the grease at the top.
- Thread the barrel back onto the head by hand. Go snug, not tight yet. You want a small gap for air to escape during priming.
- Release the follower rod. Unlock the T-handle and push the rod forward to put spring pressure on the plunger.
- Prime the grease gun. Crack the air bleeder at the head a turn, or back the barrel off a half-turn. Pump until pure grease (no air spurts) appears at the bleeder or at the coupler. Close the bleeder or snug the barrel.
- Finish tightening the barrel. Once the pump feels solid and the bleeder is closed, hand-tighten the barrel fully.
- Test on a rag. Pump a few strokes until the stream is steady. If it feels spongy, bleed again.
- Wipe everything down. Clean threads, hose, and coupler so dirt doesn’t ride to the next zerk.
If you want a manufacturer-style loading checklist, see this concise cartridge loading and priming sequence (PDF) for the same open-end-first method and a quick bleed routine.
Why The Order Matters
Open end first gives the plunger a clean path to push grease toward the head. Leaving the pull-tab on until the cartridge is seated keeps stray foil out of the barrel. Snugging the barrel before release creates a small vent path so trapped air can escape during the first few pumps.
Filling A Grease Gun Cartridge—Common Mistakes To Avoid
- Removing both seals before insertion. The foil can deform or fall in. Pop the plastic cap first, seat the tube, then pull the tab.
- Cross-threading the barrel. Start by hand and watch that the head seats square. If it binds, back off and re-start.
- Pumping with air in the head. Spongy feel or sputter at the coupler means air. Vent at the bleeder or crack the barrel a turn and pump until solid.
- Greasing dirty zerks. Grit becomes lapping compound in bearings. Wipe the nipple, click the coupler on straight, then pump.
- Over-pumping sealed points. Stop when you feel a firm rise in resistance or you see the old grease purge clean at the seal.
Prime The Grease Gun Fast
Air pockets are the #1 reason a new cartridge won’t feed. Use one of these quick bleeds:
Method 1: Use The Bleeder Screw
- Crack the bleeder one turn.
- Stroke the handle until grease, not air, exits the port.
- Close the bleeder and pump again. The handle should feel firm.
Method 2: Loosen The Barrel Nose
- Back the barrel off about a half-turn.
- Pump until the stroke firms up and the gap weeps grease.
- Snug the barrel and wipe the joint clean.
If the gun still feels soft, push the follower rod all the way in, then pull it back a few inches to reset spring pressure and repeat the bleed. The same logic matches common priming advice from pro shops and brand guides.
Grease Gun Troubleshooting On The Bench
| Symptom | Likely Cause | Quick Fix |
|---|---|---|
| Spongy handle feel | Air pocket at the head | Open bleeder or loosen barrel and pump. |
| No grease at coupler | Pull-tab left in place; plunger not seated | Open the barrel, remove tab fragment, reseat cartridge. |
| Grease leaks at threads | Barrel not tight or cross-threaded | Back off, re-thread by hand, snug fully. |
| Coupler pops off | Not fully clicked; worn jaws | Push straight on until it locks; replace worn coupler. |
| Grease weeps at zerk base | Coupler cocked or zerk loose | Square the coupler; tighten or replace the fitting. |
| Hard to pump | Cold NLGI 2 grease; tight bend in hose | Warm the cartridge; straighten the hose path. |
| Foamy discharge | Air mixed with grease | Prime again until a steady stream appears. |
Choosing The Right Grease For The Job
Match consistency to the machine and climate. Most general bearings run well on NLGI 2, a peanut-butter stiffness that handles speed and temperature across common shop work. The number comes from a test that measures how far a cone sinks into the grease. Lower numbers flow more; higher numbers are stiffer. See the NLGI grade scale for exact ranges and definitions.
Base Oils, Thickeners, And Additives
Two greases with the same NLGI number can behave differently. A lithium complex thickener with EP additives handles shock loads at couplers and pins. A calcium sulfonate complex fights water washout near hubs and marine parts. Stay with the spec in your manual; mixing types can soften or harden the blend. If you must change families, purge the old with fresh runs until the discharge looks uniform.
How To Fill A Grease Gun Cartridge In Tight Spaces
Some jobs leave little room to spin the barrel. Break loose the barrel while the gun is outside the compartment, then move into position and finish the swap by hand. A flex hose with a compact coupler clicks onto angled zerks without moving the gun body. Keep a short rigid tube in the toolbox for steady one-hand control on bench work.
Clean Up, Storage, And Disposal
- Wipe the threads and coupler. Oil on threads attracts dust and makes the next swap messy.
- Cap the hose. A rubber cap or tape over the coupler keeps grit out between jobs.
- Store upright. The plunger stays centered, and air collects at the top where it’s easy to bleed.
- Bag the spent tube. Drop in a zipper bag or lined can; follow local rules for oily waste.
Speed Card: How to Fill a Grease Gun Cartridge
Need a quick refresher at the bench? Here’s the compact flow:
- Lock the follower rod back and unscrew the barrel.
- Pop the plastic cap, insert the cartridge open end first.
- Pull the metal tab, thread the barrel on snug—not tight.
- Release the rod, bleed air at the head or by cracking the barrel.
- Tighten fully, test-pump on a rag, wipe down, and stow.
FAQ-Free Tips Seasoned Techs Swear By
- Use short strokes during priming. Small, quick pumps move air out faster than long strokes.
- Keep a spare coupler. Jaws wear over time; a fresh coupler stops leaks around zerks.
- Mark guns by grease type. A strip of colored tape on the barrel prevents cross-contamination.
- Warm stubborn cartridges. A few minutes indoors helps thick grease feed in winter.
Why This Method Works
The plunger springs push from behind, so the open end needs to face the head. Air collects at the top of the head and threads, so a small vent path is all it takes to purge it. That’s why the steps stress open-end-first loading, a short priming vent, and a firm finish. Follow this sequence and the gun feeds grease cleanly without waste.