I stopped at a yard sale this afternoon and bought the first P51 I have ever seen. It appears to be fourth quarter 1943 vintage. The filler mechanism is all plastic except for the spring. The spring is broken. Someone tried to fix the spring and gave up - sold the pen to me.

I have been studying Da Book and disassembled the pen without breaking anything, but nothing I can find, either in Da Book or on Da Web, shows whether the spring grabs the plunger or the bottom of the pellet cup. I think there is enough spring left that I can roll it partway off the plunger and decrease its diameter with some round-nosed pliers so it will grab something again, but what?

Are new springs available, or must I wait for a "parts pen" to show up?

I don't like the looks of all those tiny plastic parts in the filler unit; they look too fragile to tangle with. Maybe I will just replace the diaphragm and operate the plunger push-pull like an old bilge pump.

Any suggestions?

Paddler

Hi there,
Just had a quick look, the spring looks to be held in place by the cup that holds the pellet of the diaphragm sac and between the collar that sits in the barrel, be careful you may need heat to wiggle this off and I know that these plunger rods are very susceptable to damage from heat.
I have taken apart and re-assembled a few speedlinr and lock down fillers, though never had to with plastic rod versions. Think it would be a pretty simple operation, ust looks spose a bit daunting when you aven't done it before.

Some one I am sure will elaborate on the bes method

All the best, and let us know how you get on.

et

You can just buy a new filler unit and you are set to go... figure on spending somewhere between $25-35 for one.
Ron Zorn might have some for sale...

eckiethump is correct. The pellet cup is press fit onto the end of the plunger rod. The spring end is bent 90 deg in and captured between the cup and the pellet. The other end of the spring is large enough OD that it will not pass through the tapered collar. This provides the spring action when the filler is installed.

IF you can get your hands on another filler, use it. If not carefully try to heat the pellet cup enough that it can be slipped off the plunger rod and the spring end can be re-inserted. If the spring is not bent at an angle you will need to heat that with a micro torch (AFTER removing it from the assembly) and recreate the 90 deg bend. Then once it is cool, carefully press the cup onto the plunger with the bent portion of the spring captured between them. You may even be able to see a witness mark where the old spring was for a few decades.

Griz is right, you can purchase one, but there is a modicum of fun involved in getting these working again.

Cheers,
Sean

Aha! I see the hole in the plunger under the pellet cup. All that squinting and head-scratching. I found it when I knew what to look for.


SMG,

I agree there is fun in rehabilitating a good tool that most others consider outmoded and used up. If I didn't like to do this, I would just buy a few new pens and get cured of this collecting disease. Getting cured is easy; I have done it many times before.

Thanks to everyone for the help.

Paddler