Here you have a great Lincoln Grease Gun, and it isn’t dispensing lubricant, so what do you do? This is a common question from grease gun owners despite the brand.
Normally, dirt and debris contamination or buildup accounts for the majority of grease dispensing problems.
This can occur both with grease guns that you use daily or for grease guns that are only used occasionally. Salts and debris accumulate in your gun over time. Dirt can find its way into a gun accidentally during a change of a lubricant cartridge.
A contaminated bulk source or the separation of the lubricant can be the cause of dispensing problems and influence the performance of your grease gun. Dirty and dusty working environments as much as extreme temperatures can make a difference.
Lubricant inside the Lincoln tube is under pressure from the gun spring onto the follower assembly. When exposed to extreme harsh temperatures, lubricant separation can speed up.
Oil may seep out of your gun gradually if it has been sitting for an extended period or if it has been left in a hot environment like a car.
Base oil thickeners and additives will separate in these conditions with the thickeners blocking passages together with any debris that has been accumulated.
The liquid oil will leak from the path where it finds the least amount of resistance, and if you are using a cartridge may take place between the cartridge and the gun barrel tube.
The cartridge lip acts as a seal. The barrel tube edge and the cartridge edge must be kept clean with the tube securely closed to maintain the seal, otherwise, the gun will continue to leak.
If lubricants are left unused for too long the lubricant quality may be compromised due to oil loss. You will need a new cartridge. This cycle will lead to a loss of volume and dispensing pressure in your grease gun.
A simple cleaning may eliminate the problem.
- Remove any partially used cartridges or bulk lubricant and dispose of it properly. Never reuse cartridges in these circumstances or you may contaminate the gun a second time.
- Control the outlet checks valve, the piston chamber, or the inline check assembly as this is where most of the action occurs.
Regular clean-outs are recommended for these points. If you have limited time a rapid fuel clean-out may be sufficient until you have time to do a full clean out of your gun.
- Remove the grease tube assembly. Flip the head over and proceed to clean out the cavity.
- Fill the cavity with mineral spirits, transmission fluid, or penetrating oil. Cycle through the fluid by pumping your gun.
This should dissolve debris blockage, expelling it, and allow you to use the gun. If it proves to be insufficient, a full cleaning will be necessary.
- To proceed with a full-service cleaning, remove any remaining lubricant from the gun head cavity.
- Fully disassemble the flexible hose or extension with the check assembly.
- The coupler should be disassembled for cleaning and inspection.
- Use mineral spirits or transmission fluid with nylon bristle brushes to scrub all cavities and passages of the grease gun head.
- You may need to recede the check ball into the gun head cavity. This can be accomplished with a light but firm tap on the ball into its chamber.
- Reassemble the grease gun but do not attach the flex hose or rigid extension until after you have completed a priming sequence. This is necessary to avoid air being trapped in the gun.
- Once you have primed the grease gun, you can reattach the flex hose or rigid extension but without the coupler attached.
- Repeat the priming cycle. When fresh lubricant emerges, you can reattach the coupler.
The Flexible Extension Hose
Rigid extensions rarely need to be replaced, but flexible extension hoses do if debris has been introduced.
If your gun is not pumping with the flex hose attached do not run a wire through your hose or use reverse flushing to clean it. These actions may result in injury. You need to replace the hose.
The other principal reason grease guns will not dispense is an airlock. A pocket of air becomes trapped inside your gun, and the pumping mechanism will not budge. The quickest remedy is to bleed the air. You can do this manually or by using an air bleeder valve.
Usually, air will be trapped at the top of the gun head and will block the grease flow. To bleed your gun:
Step 1: Rotate the gun’s bottom anticlockwise a couple of turns to release the air.
Step 2: Pump while when turning the gun’s bottom.
Step 3: Lubricant will begin to flow from the gun as the air bleeds out. Now, close the gun bottom snugly.
If the gun has an air bleeder valve use it instead. Unscrew the bleeder valve several turns. A “pop” will sound, and grease may flow from the valve. Close the bleeder valve by screwing it and clean off any lubricant residue.
Always fill your gun in a clean environment to prevent debris and contamination from entering the dispensing chamber.
Lubricant Quality and Storage
Always use good quality grease in your gun and monitor the usage to prevent leftover grease from remaining in the gun too long.
If you will not be using your gun for an extended period, or if you store it in an environment that offers harsh temperatures like your car, remove the cartridge or remaining bulk-loaded grease once you have finished using the gun.
Clean out the dispensing chamber thoroughly and store your gun in a cool and dry location. If the grease cartridge is only partially used cover both ends and store the cartridge with the gun until the next use.