I've searched a lot for ideas. I'm curious what input you guys have for getting out swollen glow plugs. I have just one that is stuck. It threads all the way but won't pull out. I haven't pulled real hard because I can't afford for the truck to be down right now.
I found this tool: http://jjandaracing.com/en-us/dept_9.html
It's pretty pricey, but might be worth it to avoid other hassle.
Someone at another forum suggested unscrewing it and then firing up the engine to blow the GP out. Sounds crazy, but also sounds easy. I'm not sure I have the nerve to try.