"Can you give me some advice on how to use a grease gun properly?"
When lubricating equipment with a grease gun, it is important to know precisely how much lubricant needs to be applied per cycle and how much lubricant the grease gun will produce per shot. Grease guns can produce between 1 gram and 1.5 grams per shot. This can result in significant overlubrication per point unless the output is known.
Grease guns are capable of producing several thousand psi per stroke. This kind of pressure can certainly blow out bearing seals and shields. If a careless approach is taken when using the grease gun, then it is highly likely that the equipment will be overpressurized and overlubricated. When this occurs, particularly with a bearing, then the likelihood that the bearing can see its rated lifecycle is greatly reduced.
Whether the gun is filled with oil or grease, the practitioner should be precise with the use of the gun, beginning with an analysis of the bearing dimensions and calculation of the required amount of grease per cycle, followed by an analysis of the amount of output per cycle of the gun.
When working the grease gun lever arm, never hold the nozzle onto the grease fitting. Also, when cycling the lever arm, be conscious of the risk of overpressurization and do not force the lever arm if there is strong back pressure.
Use the following tips to maintain your grease guns and fittings.