Piston Repair - How To Guide For The Beginner

[Jennings]

Hi Folks...I'm hoping to learn the basics of piston renewal, using a Pelikan 120 with a leaky piston as a start point. Can anyone point me to some guide material for how to get this kind of pen dismantled, and how to fashion and fit a replacement piston?

[Ron Z]

The early Pelikans are fairly easy for the amateur to repair. Not so the modern Pelikans.

 

The modern 120 uses a molded plastic piston seal that snaps onto the end of the piston. It's designed to be replaced with another molded piece, so you can't make one out of cork or use 0-rings. Even if tempted to try to make something, the piston shaft itself is flat with "threads" cut into the sides. It isn't thick enough to drill, tap and then use a screw to hold anything that you could make onto the end.

 

The whole mechanism is a snap fit into the barrel which means that it locks into the barrel with a snap as it's pushed into place. It takes some sill and experience to get it out of the barrel. If you value the pen, don't learn how to get it out on this one.

[Jennings]

Thanks Ron for the tip off...perhaps this isn't something I should attempt myself then. Then pen looks to be a 1950s 120, judging by the look of it, though I can't be sure. I might send it out for service instead then.

[Jennings]

The barrel has a stamp which reads J21 292...is there any way to date the pen from this, or is it not any kind of datable code?

[whych]

Which type of 120 is it?

The early ones with the body thicker than the piston knob have a flat edge on the piston sleeve (you can check this by unscrewing the piston as if you were gong to fill the pen) It needs a special spanner to unscrew the sleeve which is a left hand thread.

 

The later ones have the body and knob the same diameter. The piston just unscrews. Unscrew like you are filling the pen and keep turning.

 

The seals aren't so easy to find replacements for, but some silicon grease may help to bring it back to life.

You can grease the inside of the barrel by unscrewing the nib and using a toothpick to get into the body and apply the grease.

Work the piston up and down and leave for a wile and keep doing it every few hours.

Then try filling with water and see if it leaks. If not, then wash the excess grease out the pen and nib with warm water and you're done. If you don't do this, the excess silicon will clog the nib.

Edited January 20, 2013 by whych

[Jennings]

Thanks whych...Looks like mine's an early 120 then...the barrel is thicker than the piston knob, and I can see a flat edge on the piston sleeve. I guess I'd need the special spanner to unscrew the piston mechnism then? Thanks for the tips on the grease...I'll give that go if I can safely unscrew the nib and/or barrel.

[Jennings]

Update...after a bit of net searching, my 120 appears to be a mark I version. The silicon grease idea has worked relatively well, though I can see some tiny droplets which have passed by the piston seal. It's not a full on leak or flood though, but clearly is only a temporary measure.

 

Were these mark I pens ones with snap in mechanisms? There's only one flat edge visible on the piston housing threads at the screw cap end. In order to get to the piston on these pens, does the piston housing unscrew out of the pen, pull out of the pen, or is this the version that's not even worth attempting?

Edited February 18, 2013 by Jennings

[whych]

You knock it out the same as on the Pelikan 140, 400 and M series do. There is a recent link to a German board with instructions in German in the Pelikan section I think.

http://www.penexchange.de/forum_neu/viewtopic.php?f=3&t=2920

You should get the idea from the diagrams.

Marshall and Oldfield in their book hold the pen with one hand, mallet in the other and knock the piston out. This probably has the advantage that you can't hit too hard to damage the pen because your hand acts as a shock absorber.

Edited February 18, 2013 by whych

[Jennings]

Thanks whych...that's a really useful bit of info, and I love the pictorial link! Not least because I was pleasently surprised how much high school German I remembered!!! I'll take the tip on going lightly with the knocking out too. I'll try it and give the insides a better clean and grease up and see what that achieves.

[Jennings]

Well I've managed to gently knock out the mechanism and clean it up. The seal is one of those white rubbery plastic things that push-fits onto the end of the piston rod. I can see why it's leaking...there's a sort of wear/gouge down one side of it from top to bottom which is probably enough to let a slow leak through gradually. Explains why the greasing was only partially successful. Is it possible to obtain a replacement for this kind of seal?

[whych]

Try using some rubber o-rings (you may need 2). If you have a hardware store that sells them singly from a box take the pen in and see if you can get one to fit.

If the piston rod is hollow, you need to block it.

[crazypencollector]

I started restoring pistons now ,with rubber and wonder is that is as good as cork.....Cork is probably better?