Jeff, I had to go to the auto parts store and buy three grease guns in order to get two that worked - one for my moly joints and one for my lithium joints. I think the OEM brand that Autozone sells is what worked for me, but the NAPA one that I had was doing what you described.
Rising Sun Bio
2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering,
no more Sanden OBA
1FZ-FE factory lockers +
Safari intercooled turbo, CDL switch, cup holder, Metric TLC leather, heated seats, JDM switches, PUMA OBA.
Warn M12000 waiting for a bumper.
Limited TRD 2UZ-FE SOLD