Agree with applying mild heat to affected joints, but…..
I had a few zerks that would not pass any grease upon restoral of my 51 panel.
I went out and bought a collection of new zerks in straight, angled, and 90 degree orientations and replaced ALL of them. However, I discovered that the reach of the threads on some of the original zerks was a lot less than on the replacements. Hence, I had to back them up slightly (before bottoming out) to allow the grease to actually pass through and into the joint. This was particularly true on the king pin
fittings. Once the grease got to where it was needed I just snugged them up a turn or so. I found that even with heat …. some of the original zerks were just too clogged to work. my experience, anyway….
mike
