MB 149 helical rod separated from knob

[guyy]

I picked up an eBay 149 at a parts pen price. I thought i saw a nice xf nib through the fuzz of the pictures. As expected it came with undisclosed problems. In this case, it was that the helical rod has separated from the piston knob. Is there a fix for this aside from replacing the knob and helical rod as a unit? Here are some pictures:

https://imgur.com/a/gJZJYh8

[Chrissy]

There's no fix that I've ever heard of or seen. I can't think of anything that would ever hold it together so that it would work as a piston again. It looks like there has already been some sort of attempt at repair inside the end cone. That should only contain a C clip that holds the other end of the rod.
It needs at the very least a new unit and probably a new cone.
Bear in mind that a level one service at Montblanc would replace everything to do with the piston not just the rod, and it would cost about $80

[guyy]

Well, there’s this method, which was posted over at that other pen site:

http://www.fountainpennetwork.com/forum/topic/276873-another-d-i-y-149-repair-pictorial/#entry3162375

However, Custom Pen Parts hasn’t had those rods for a while.

Since everything else on the pen is in good shape and i prefer the 1970s pens, i’d rather replace only what’s broken. My understanding is that MB would replace the filling unit with the current one, which would require a new barrel, which would require a new feed and a new cap. It would end up being a current production pen with an old nib.

[Chrissy]

Then you need to work something else out for yourself. Good luck with your pen. :)

(Montblanc would not replace the cap in a level one service. If you wanted to keep the feed, they can do that too. The filling unit is the same apart from the fact it would have a brass screw thread rather than the breakable plastic one.)

[guyy]

I got a replacement piston knob/helical rod and installed it.

I measured the capacity and got 2.3ml which is right for certain vintages of the 149. Not that i really need a boatload of ink for a pen with a very fine nib, but i suppose some might prefer more ink capacity.