Hi there
I have been trying to restore a Pelikan 400 to working order in the last couple of days. So far, I have managed to:
1) clean the pen to an acceptable level
2) unscrew the nib & free the stuck piston
3) lubricate inside of the barrell with silicone.
The blind cap (connected to the grooved piston shaft) now screws in and out and the piston, accordingly, moves forward and backward.
One problem: I can't get the blind cap to screw back all the way to the pen end, it just stops about two milllimiters short of it, and I can't figure out why.
Does any of you readers have a clue about possible causes of this?
Thanks!
Montague

Not quite sure, maybe check with Chartpak the design may have not changed that much over the years that they may be able to help you out.

Good luck

I'd send it to Chartpak. It sounds as if the piston rod is a bit out of whack. It may have come out of the gear that turns it and slipped back in one rotation off.
Alternatively, I believe that Richard Binder could fix it for you (as could I), but Chartpak ought to do it for free.