Grease Gun Twilight Zone

[Beltzington]

Lubing some fittings as I have done 100's of times before and all of a sudden grease starts emerging from a previously unseen hole on the grease gun. Disassembly seemed to indicate this particular hole was there to relieve excess pressure. Sure enough no grease was getting thru the hose. I found I was unable to pass a small pick more than 1" on either end of the grease hose. Irritated I drilled both ends out with a 1/8 bit. Grease now flows but I am curious why the failure and why the hoses would be designed with such small diameter passage. Also I wasted half a tube of $10 poly-grease and ruined a good pair of jeans. Lincoln Electric grease gun previously has functioned flawlessly. Thoughts?

 

[Texasmark]

My experience with a dozen or so over the years, pneumatic and manual is that somewhere on the gun is a mechanism to relieve air in the chamber on refill so that the spring can push the grease up to the top and be available for the piston to push it out.

On one I recall, the relief is in the side of the cap and it is exposed until you get about 3 threads from tight. I usually fill it and tighten all the way, then back it off letting the air out till I see grease and then run it back up tight.

on others there is a screw in the top of the cap you loosen for the same purpose but if you accidentally back it all the way out............you guessed it, you have a mess.

Mark