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Quick Answer
Yes, you can refill a grease gun cartridge once it is empty. The process involves thoroughly cleaning out the old grease, refilling the cartridge with new grease, and priming the grease gun so the new grease can flow properly. With the right supplies and steps, refilling a grease cartridge can save time and money compared to constantly buying new cartridges.
What is a Grease Gun?
A grease gun is a tool used to apply lubricant or grease to mechanical equipment and machinery. It works by pumping grease from a refillable cartridge through a hose and nozzle.
Grease guns allow you to apply the exact amount of grease needed to lubricate equipment. They are commonly used for lubricating bearings, universal joints, fittings, and other parts on vehicles, heavy machinery, and industrial equipment.
Here are some key features and components of a typical grease gun:
– Cartridge – This is the canister or tank that holds the grease. Cartridges are refillable and sold separately from the grease gun itself. Common sizes are 14 oz, 26 oz, and 120 lb bulk cartridges.
– Pump – A manual lever or pistol-grip pump is used to build pressure and push grease from the cartridge through the hose. The pump attaches directly to the cartridge.
– Hose – A flexible rubber hose 3-4 feet long connects to the pump and cartridge at one end and has a nozzle at the other end for applying grease.
– Nozzle – A head with a small opening that allows grease to be precisely applied and controls grease flow. Nozzles can be straight, bent, or flexible.
Why Refill a Grease Cartridge?
There are several benefits to refilling a grease gun cartridge instead of replacing it:
Cost Savings
Refilling a cartridge costs a fraction of what a new pre-filled cartridge does. The grease itself is fairly affordable if bought in bulk quantities. Reusing the original cartridge over and over avoids the added cost of cartridges.
Reduced Waste
Throwing out empty cartridges generates unnecessary waste and plastic pollution. Refilling the same cartridge extends its life cycle and is more sustainable.
Convenience
Making your own fresh batch of grease means you always have it on hand exactly when you need it. You don’t have to stop work to go out and buy new cartridges.
Customization
When refilling cartridges yourself, you can customize the grease’s thickness and consistency for your specific application and equipment.
How to Refill a Grease Cartridge
Refilling a grease gun cartridge is a simple process that can be done in a few steps:
Supplies Needed
– Grease gun
– Empty cartridge from grease gun
– Automotive or multipurpose grease. Common types include lithium complex, calcium sulfonate, polyurea, aluminum complex etc.
– Sturdy metal spatula or spoon
– Rag or paper towels
– Bucket or container for used grease
Step 1 – Clean the Cartridge
– Unscrew the spent cartridge from the grease gun pump and remove it. Make sure to wipe off any grease from the threads.
– Take the cartridge and wipe off any dirt, debris or old hardened grease from the exterior using a rag.
– Find the opening on the bottom where used grease expelled from. Take a stiff brush and scrub the interior walls through the opening to remove all remaining grease buildup.
– Use the rag to wipe any remaining grease traces out of the interior. The cleaner the better.
Step 2 – Fill with New Grease
– Place the open end of the cartridge into the container of new grease. Begin packing grease into the cavity using a spoon or spatula.
– Fill it to about 80% capacity. Air space allows room for priming later.
– Add grease slowly to prevent air pockets. Tamp down and compress with the spoon intermittently.
Step 3 – Prime the Cartridge
– Reattach the refilled cartridge back onto the grease gun securely.
– Unhook the hose if connected. Hold the gun upright with the nozzle pointing up.
– Work the pump lever 10-15 times. This will push out any trapped air pockets and fill the hose with grease.
– Reconnect the hose once primed. The grease gun is now ready for reuse.
Tips for Refilling Grease Cartridges
Follow these tips when refilling grease gun cartridges:
– Completely use up old grease in the cartridge before refilling. Remaining pockets of old grease can contaminate the new batch.
– Match the thickness and consistency of new grease to what the manual recommends for that grease gun model.
– When buying bulk grease, only portion out what is needed for a single refill into a separate container. Don’t contaminate the whole tub.
– Store any leftover grease in sealed containers to prevent contamination.
– Set some paper down underneath when refilling to catch any spills and drips.
– Be prepared to get a bit messy. Wear gloves and have rags ready.
– Refill cartridges immediately before use. Don’t store refilled cartridges for prolonged periods.
– Monitor grease color when lubricating afterwards. Discontinue use if grease becomes contaminated.
Best Greases for Refilling Cartridges
Here are some top-rated grease varieties for refilling grease gun cartridges:
Lithium Complex Grease
Lithium complex is one of the most versatile multipurpose greases. It adheres well and withstands high temperatures and pressure. It’s suitable for all types of general automotive and industrial uses. Brands like Valvoline and Lucas offer lithium complex greases optimal for grease gun refills.
| Brand | Grease Name |
| Valvoline | Premium Blue Grease |
| Lucas | X-Tra Heavy Duty Grease |
Calcium Sulfonate Grease
Calcium sulfonate greases excel in extreme temperature environments ranging from -40°F to over 500°F. They resist water washout making them ideal for outdoor machinery. Popular options are Lubriplate’s Calcium Sulfonate EP 2 and Mystik JT-6 Hi-Temp Grease.
Polyurea Grease
Polyurea grease has excellent mechanical stability allowing it to withstand high loads and pressures. It resists oxidation and thermal breakdown. Chevron’s Polyurea E.P. 2 is a top choice.
Aluminum Complex
Aluminum complex greases like Shell’s Alvania RL 3 provide superb performance across a wide temperature span. They protect metal parts extremely well with anti-wear additives.
Problems When Refilling Cartridges
Refilling grease cartridges is fairly straightforward, but here are some potential problems to watch out for:
– Grease Has Short Shelf Life: Some low quality greases can degrade within 1-2 months. Use high performance brands with antioxidant additives that prolong shelf life. Avoid buying more grease than you’ll need.
– No Grease Flow: If grease won’t flow through the nozzle, the cartridge may be clogged from hardened grease. Take apart the grease gun and thoroughly clean each component. Heat up hardened grease clumps to soften them for removal.
– Air Pockets in Grease: If you pump air bubbles instead of a smooth grease stream, there’s air trapped inside the cartridge. Open it back up and repack the grease more densely without gaps. Prime it again.
– Grease Leaks: Worn out cartridge seals or damaged threads can cause grease to leak out around the pump connection. Inspect the hardware and replace any faulty o-rings or seals.
– Contaminated Grease: Foreign particles and moisture contamination will degrade grease performance. Use clean tools and containers. Store grease in sealed buckets to prevent exposure.
When to Get a New Cartridge
While designed to be reusable, even the highest quality grease gun cartridges eventually wear out and need full replacement. Some signs it’s time to retire a cartridge include:
– Visible cracks or defects in the metal canister walls. Dents that distort the circular shape.
– Threads around the opening are worn, stripped, or cross-threaded. Pump won’t properly fasten.
– Leaking seals or discharge plug despite new o-rings and proper installation.
– Inside is stained dark color and scaly residue buildup that can’t be removed.
– Pumping lever feels abnormally loose or lacks pressure. Broken interior spring.
For standard grease gun use, most cartridges will last approximately 5-10 refills before replacement is needed. Proper cleaning and care extends usefulness.
Conclusion
Refilling grease gun cartridges is an easy DIY process that saves time and money compared to buying new cartridges each time. With the right grease selection and refill technique, a high quality cartridge can be reused for many maintenance sessions before replacement is required. Proper cleaning and priming is key to ensure smooth grease flow without contamination. Refilling cartridges yourself allows customization of grease for your specific equipment needs.