How to Load a Grease Gun Cartridge
Pack the Grease Gun Head
Prevent air locks by filling the grease gun head before adding the new cartridge. Scoop any remaining grease out of the old cartridge and pack it into the head.
Insert the new cartridge and screw on the barrel until it seats against the head. Then back it off two turns and release the spring tension. The remaining air should bleed out through the loose threads. Finish tightening the barrel.
Burp From the Top
If you’ve done that but still have an air lock, remove the plug. Unscrew the plug on the head of the grease gun, but keep it positioned directly over the hole. Screw it back in as soon as the air bubble clears.