Usually, when a zerk is locked up, it's on account of dried up crusty grease and mung under the Zerk and blocking flow.
Worse, it always seems to be on pins that are either a ******* to pull, or are a PITA to get back in, once pulled.
Keeping up on the greasing is the key, but we all brain fart one or two now and then.
I figured out a long time ago(Uncle Fred smacking me upside the head) heat cures lotsa things.
An overnight soak with Kroil squirted under the Zerk, followed by warming things up with the heat gun does wonder on about 80%.
The remaining 20% seem to either need the pin pulled, or the Zerk chucked into a vice and heated up with a torch, untill they pop out a little terd of crusty grease.
The really ugly, rusty, woefully neglected, and impossible zerks, are thier own thing.
If they are that bad, I learned that it's my pennance to fight the pins, or cuss myself while replacing a bearing, and lamenting my inattention.
