With the fitting out take something small that will fit up into the grease fitting hole and dig out some of the old grease, if it has hardened that might help. Another and probably better idea is to move the joint to get it in a different position [articulate, oscillate the joint] sometimes it will take in a different position, that works most of the time. Another thing you might try is to move the joint back and forth a few times to heat up the old grease and then try pumping in new grease. After you get it to taking pump grease into the joint a little after you see grease coming out of the joint, that will or might push out the old grease. When I mentioned trying to put grease in by cutting it left or right or oscillate it go from the extreme to the extreme movement of the joint . Someone mentioned something that made good sense to me and that was to do the eight hour service every 5 hours instead that makes it easier to keep track of your service schedule and also might help keep you from having fittings that won't take grease. I hope this helps.
