The grease gun is a basic tool. Almost everyone has seen them hanging on the wall somewhere. They seem simple enough: You squeeze the handle and grease comes out, right? Well, there is more to know than just that. To use one efficiently and properly takes a little more know-how, but it's easy enough to learn.
On one end of the grease gun is the rod handle. This is used to press the grease to the other end of the gun. The rod handle fits into the end cap. It screws into the barrel, which also screws into the head. On the head there may or may not be a loader fitting and an air relief valve. They are used to relieve the pumping pressure before opening the gun. Coming off the head in one direction is the handle which you use to pump the grease out of the grease gun. Coming out in the other direction is an extension pipe (or hose) and on the end of that is the coupler (which is where the grease comes out). The most common type of coupler is the 1/8-inch NPT (national pipe thread) coupler. There is also the flush fitting coupler, which is a common coupler. Different types and styles are used and you just need to find the ones that fit your needs.
A grease gun exerts high pressure when you pump the handle. Some guns will reach 15,000 PSI (pounds per square inch). A bearing seal cannot withstand that much pressure and would easily rupture from the force of the grease gun. Once the seal is blown out, all kinds of contaminants can get into the bearings and cause premature wear, shortening the life of the bearing. It is best to squirt only two to three pumps of the handle into each bearing. Also, there are a lot of different kinds of greases available. The most common are sodium, barium, lithium, calcium and aluminum based grease. Multipurpose greases incorporate two or more of these types to cover a broader spectrum of applications. There are also high-pressure greases and many other kinds as well. Be sure to label your grease gun so you don't forget which type of grease is in that gun.
Be careful when opening up and inserting a new tube into the grease gun. Do not allow dirt or any other contaminants to get into the grease. Eventually that dirt will be pushed into the bearings.
Wipe off the coupling and fitting before and after each use to ensure that there isn't any dirt contaminating the grease.
Be careful when using a grease gun around machinery and moving parts. It is best to turn off any equipment before performing maintenance.
