Properly loading a grease gun can be trickier than you might think. I can tell you from experience that doing it incorrectly will lead to grease on everything and a (formally) good grease cartridge in the trash. To avoid the frustration and waste, check out our video instructions on how to load a grease gun. Step-by-step instructions are also included below.
Watch: How to Load a Grease Gun
Time needed: 10 minutes.
Step-by-step: How to load a grease gun
- Remove old cartridge and reset spring
First, unscrew the end cap from the grease gun and remove the empty cartridge. Install the end cap and retract the spring by pulling the plunger-rod handle and twisting and locking it in place.
- Load new grease cartridge
Unscrew the body of the grease gun. Remove the plastic cap from the new grease cartridge. You’ll notice the grease doesn’t come all the way to the top of the cartridge, which is by design. Insert this end into the body of the gun first. You may need to twist the cartridge slightly to seat it all the way.
- Remove seal
Next, remove the seal from the other end of the grease cartridge. On most cartridges, it’ll be an aluminum tab that you pop and peel off. Some smaller cartridges may have a foil seal. Ensure it’s completely removed and no small pieces are left behind.
- Install grease gun body
With the cartridge loaded, screw the body onto the head of the grease gun. Don’t fully tighten it, however; catch a few threads and leave it loose for now. Twist the plunger-rod handle and release the spring. Push the plunger-rod handle all the way into the grease gun. Now you can tighten the grease-gun body completely. Waiting until now to tighten it all the way helps remove entrapped air that can impede the gun’s ability to pump grease.
- Prime grease gun
With a rag handy, pump the handle to prime the grease gun until grease begins to flow. It may take several handle-pumps to remove all the air from the gun, so be patient.
- Remove the plug and continue priming, if needed
It’s common for the grease gun to fail to prime due to entrapped air in the system. If this happens to you, remove the plug on the end of the grease-gun head and continue priming. This shortens the distance the grease must travel through the system and helps remove the air. Once grease emerges from the plug opening, install the plug and continue priming until the gun is pumping grease properly.
How to use a grease gun
Now that you’ve seen how to load a grease gun, it’s time to put it to use. Here are a few guidelines to follow when greasing equipment.
Use the correct grease
First and foremost, make sure the grease you’re using meets the specifications given in the owner’s manual or service manual. Most applications specify either NLGI #1 or NLGI #2 grease. NLGI #1 is typically reserved for cold-weather applications since it’s a little softer and easier to pump.
Your application may also specify using a grease that meets the GC-LB specification, which is a common spec for automotive bearings.
If you have questions, consult AMSOIL Technical Services ([email protected] or 715-399-TECH) to discuss your greasing needs and get the proper grease for your application.
Avoid mixing greases
Different greases use different base oils and thickeners, which can be incompatible. Mixing incompatible greases can cause the grease to break down and fail to provide adequate lubrication. When changing greases, clean the equipment of the old grease when possible or flush it with a liberal amount of fresh grease while the mechanism is in operation. Closely monitor the system for any inconsistencies.
Keep it clean
Maintaining a clean work environment is important when greasing equipment. Wipe grease fittings clean prior to injecting grease to prevent contaminant ingestion. Wipe the fitting after greasing, too. Finally, wipe excess grease off the gun nozzle and cover it with a cap to keep it clean during storage.
A grease gun is capable of producing pressures as high as 15,000 psi. This greatly exceeds the pressure most bearing seals are designed to withstand. Over-greasing can easily rupture seals, which leads to increased friction, heat and, eventually, maintenance and downtime.
Proper greasing requires little or no weight behind the grease gun handle. As soon as you feel backpressure, stop greasing. It’s tempting to think adding a few extra shots of grease is beneficial, but it does more harm than good. Backpressure means the cavity is close to, or completely full, so stop greasing.
Some greases are harder to pump than others. That is by design. And some applications, like pins and bushings, require more force to push the grease into place. In general, though, if you have to stand on the handle or get a cheater bar, something is wrong.
Use high-quality grease
Finally, make sure you use a high-quality grease, like AMSOIL synthetic grease. We formulate our greases with durable synthetic base oils and high-quality thickeners so they provide excellent adhesion and wear protection. They withstand heavy loads, remain in place despite rigorous use and fight corrosion for long component life.