Repairing Vintage Montblanc 420

[enitharmon]

My partner tracked down and bought me a vintage MB 420 (c. 1972) as a Christmas present. I'm not supposed to know how much it was but I do and it made my eyes water.

 

It wrote like a dream for a while – the soft nib took a bit of getting used to but once I did it was great. And then, when I went to replace an empty cartridge, I found that the old cartridge was stuck in the barrel and wouldn't shift suggesting that some other part of the nib unit had come adrft.

 

I took it to my nearest MB service centre, an upmarket jeweller's in a town an hour's drive away and they sent it off to MB for a repair estimate. Weeks went by, and then this morning I got a call to say that MB wouldn't do anything because the pen was too old.

 

Is it likely that an independent repairer would be able to repair my Montblanc? And if so, where would I be likely to find one?

 

 

[FredRydr]

Pardon me while I rack my brain out, but there's a pen repairman in Edinburgh. I corresponded with him years ago. Let me think (while someone else posts his name!).

 

Fred

[jar]

Welcome home. Pull up a stump and set a spell.

 

Can you post some pictures to show us the stuck cartridge?

[FredRydr]

It's Eric!

 

Here he is: http://eckiethump.webs.com Contact page: http://eckiethump.webs.com/contactdetails.htm

 

Fred

Edited March 24, 2015 by FredRydr

[enitharmon]

Can you post some pictures to show us the stuck cartridge?

I could, but I'll have to get it back from the shop first!

[mr T.]

This is an older thread, but I have a similar problem. In my Montblanc Classic 420 (in the so called 'Patronenfüller' version), the converter was stuck in the barrel an could not be removed without screwing a broken part out. The part with the nib, grip, and feed are stuck in the cap. The the part with the screw thread (that connects the grip with the barrel) is broken. There are no (visible) hairlines or cracks in the barrel or the cap. This pen was used in the past but was stored uninked for more than a year. Bought it at an official Montblanc dealer as NOS. Not sure why this happened but it almost looks like some plastic parts shrunk or failed due to 'plastic fatigue'. What I understand here is that Montblanc doesn't repair these pens anymore. So be aware this can happen if one owns one or wants to buy this as vintage.

[CS388]

Long time since I had one of this series. Has the transparent part completely sheared off? I see the nibble on the edge, but it's a pretty clean break?

 

To get the parts out of the cap, I'd use a hair dryer (or other form of gentle heat) on the outside, then grip the stuck parts with something (eg tweezers or a pencil eraser carved to the rough shape) and try to turn it back and forth, until it starts to move, then screw it back out of the cap. Once they have relinquished their hold, they tend to come out easily enough. There are exceptions, of course! Fingers crossed.

 

Re repair: I think you will be very lucky to find a replacement part - same as most of the vintage market.

It's worth looking around, as replacing the broken part would be the most effective repair.

Re your first picture of the transparent part, if most of the lower smooth part is buried in the section (when assembled), you may be able to affect a repair with a suitable adhesive? You'll only know this, once you have all the parts out. It could keep the pen working as you continue looking for a replacement part.

 

A lot of guesswork in this post, I don't have any of these pens, anymore.

If you have no luck, it may be worth posting your query in the Repairs Q&A sub-forum.

 

Good luck.

[mr T.]

On 8/28/2025 at 6:52 PM, CS388 said:

Has the transparent part completely sheared off? I see the nibble on the edge, but it's a pretty clean break?

The transparent part has indeed completely sheared of. Tried to remove the other transparent part out of the cap with tweezers but unfortunately without succes. I'm not sure if it is possible to remove the clip and/or the top of the cap without damaging the cap. If it is possible, maybe the part with the nib, feed and grip can be pushed back from the top of the cap.

[CS388]

I'm surprised, the heat normally does the trick. 

 

You could try soaking the whole cap and parts in water overnight? It may penetrate any dried ink holding the threads.

To get a better grip (to screw the parts out) you can roughly shave a cork to insert and get a friction purchase on the section.

 

 

 

 

[mr T.]

15 hours ago, CS388 said:

I'm surprised, the heat normally does the trick.  You could try soaking the whole cap and parts in water overnight? It may penetrate any dried ink holding the threads.

To get a better grip (to screw the parts out) you can roughly shave a cork to insert and get a friction purchase on the section.

I soaked the whole cap (with the other parts still in it) in hot (close to boiling) water and in water with some added dish soap. The grip, nib and feed didn't even after that come out of the cap unfortunately but did some (diluted) ink did leak from the top of the cap. Also tried without succes to remove the metal parts on top of the cap and tried to remove the clip. Next I will freeze the cap and try something with heat (water or hair dryer) again. I am well aware that this pen will likely to be a full write off, that in the end the only part that will be worth saving is the 14K nib and that replacement parts are simply not available.    

[mr T.]

Did succeed to remove the grip, nib and feed from the barrel with the help of some boiling water, tweezers, a small scredriver and a hammer. What I also did was removing the top of the cap (the part with the Montblanc logo). That part was screwed and glued into the the green plastic part that was inside the cap. Once the part with the logo was removed, the clip could be removed. After the removal of the clip and the grip, nib, feed, a metal part inside and the green part (spring loaded with a screw thread) could be removed with a small screw driver, tweezers and a hammer.

 

After removing these parts, the cause of the problem was obvious: the broken/sheared off transparent plastic part. The transparent plastic part is probably the weakest part in the construction of the Montblanc 420. Did glue the broken part back into the grip, placed the (spring loaded) green plastic part back into the cap, pushed the clip back into the (outside) of the cap and on top of that, screwed the part with the Montblanc logo back into the cap. The last part that was put back into the cap was the round metal part (that had to be pushed back with a screw driver as far as possible into the cap). This parts seems to have a function when posting the pen and when putting the cap on the pen. It also scratches the grip.

 

So in the end, the pen was fixed and could be filled with ink again. The barrel and grip still needs cleaning and polishing though. 

[CS388]

This is good news.

Congratulations.

Hope you enjoy using it.

[Opooh]

Nice job done.

[mr T.]

2 hours ago, digitorum- Leonardo_W said:

Is it written 420 on the cap ring of your pen ? 

There is no "420" on the ring. On the ring is written in very small engraved letters: "Montblanc Germany"

[Opooh]

Found pics of these red and green Carrera

[mr T.]

On 9/11/2025 at 7:23 PM, Opooh said:

Found pics of these red and green Carrera

There seems to be more versions around. A lot of Carrera's seem to have perforated metal clips.

 

On 9/11/2025 at 9:29 PM, digitorum- Leonardo_W said:

I suspect, and I might be mistaken as I didn't see clear pictures of some parts of your pen, that it might be a different model. 

Here is a Montblanc 420 and you can see the nib, I have one of those, thats why I chimed in.. I found out some vendors online listing what looks to be a 221-221p as a 420, they do not carry any markings other than Montblanc Germany on the cap ring:

You could be right but... mine has the same '585 K' text on the nib (without the Montblanc symbol/logo), the same color and the same ink window as your 420. Besides the marking/text on the ring, the main difference is the slightly different design of the grip. This specifically where the nib and feed are placed into the grip. Maybe mine is a 320 and not a 420. However, from what I've seen, the 320 has "320" engraved on the ring. It's all a bit confusing. What I do know: mine is unlikely a counterfeit one because it has been bought at a B&M shop that was an official MB dealer at the time and that the part that has been sheared of is used in the  121, 126, 221, 227, 320 and 420. 

[austollie]

What makes budget MBs of the era so special is that you can take them apart for repair.  I had the equivalent clear plastic part on a Pelikano shear off and that can't be repaired.  I've attached a pic of a disassembled MB Carrera.  These are easy to take apart and repair, e.g. to attend to a broken feed or a bent cap clip (both of which I've had to deal with).

[Opooh]

On 9/14/2025 at 3:53 PM, digitorum- Leonardo_W said:

 

Couldn't agree more and you can find many broken pens that become donors to other pens. Easy to disassemble/clean/repair. 

That is also true for the Meisterstück MB, except you need some tools. Although there is an item on you tube they use a paperclip as tool.