Montblanc 146 Piston Problems And Quality Control

[maclink]

Thanks for the pointers.  I had to check here first in case I was missing something.  I'll have another go at it in a couple weeks when time and concentration allow for it.

[gyasko]

21 hours ago, maclink said:

One of my MB 146's, I bought pre-owned.  The piston has been quite stiff.  Additionally, there's about a half turn of 'play' in the piston knob before it actually moves the piston. 

 

I got myself one of those tools for the piston and unscrewed it.  I couldn't get the piston seal and rod out.  I pulled until I felt I would break something if I pulled harder.  I then turned the piston until the threaded part unscrewed from the piston rod which remained stuck.  I regret not having taken a pic or two during the ordeal but the parts I'm referring to are demonstrated here:

 

 

I copied and pasted a link for this image from a post made by 'talkinghead'.

 

The piston seal seems to need some lubricating and this is why it's so stiff and stuck!! 

 

Eventually, I gave in lest I break something and simply reassembled.  Things are back to the way they were before.  😰

 

Any ideas?

 

 

Frontal attack?  I’d always prefer to open the back end, but if that’s not possible, you can do it the other way. In fact, you have to go in the front with some MBs like 1960s 149s (unless you want to pull the the friction fit piston mechanism, an even riskier maneuver).  The tool & method varies depending on the vintage of your 146.-

[gyasko]

Another note:

 

Definitely try getting water in the barrel.  If the piston is completely stuck, try blasting  the feed with a syringe.  Sometimes you can get water in by soaking or even just by holding under the tap.  

[Pen Nut]

On the flush & general cleaning here is a couple of posts from a good few years ago now. I still use the same method when required.

 

 

 

[JCC123]

On 2/13/2021 at 11:17 AM, maclink said:

One of my MB 146's, I bought pre-owned.  The piston has been quite stiff.  Additionally, there's about a half turn of 'play' in the piston knob before it actually moves the piston. 

 

I got myself one of those tools for the piston and unscrewed it.  I couldn't get the piston seal and rod out.  I pulled until I felt I would break something if I pulled harder.  I then turned the piston until the threaded part unscrewed from the piston rod which remained stuck.  I regret not having taken a pic or two during the ordeal but the parts I'm referring to are demonstrated here:

 

 

I copied and pasted a link for this image from a post made by 'talkinghead'.

 

The piston seal seems to need some lubricating and this is why it's so stiff and stuck!! 

 

Eventually, I gave in lest I break something and simply reassembled.  Things are back to the way they were before.  😰

 

Any ideas?

 

I believe you can, after loosening the rear piston assembly, continue to unscrew the back piston screw and rear cap? Once you removed that you can then just pull out the brass assembly screw leaving you with just the piston rod and piston in the barrel. You should then be able to yank it out. You can also look into the barrel with a flashlight to see if there's any dried ink or other obstruction keeping it from sliding out.

[maclink]

1 hour ago, JCC123 said:

I believe you can, after loosening the rear piston assembly, continue to unscrew the back piston screw and rear cap? Once you removed that you can then just pull out the brass assembly screw leaving you with just the piston rod and piston in the barrel. You should then be able to yank it out. You can also look into the barrel with a flashlight to see if there's any dried ink or other obstruction keeping it from sliding out.

Keep it coming.  🙂

 

I'll be more adventurous next time.  It was my first attempt at a disassembly that was stubborn and I had not attempted disassembling a MB before.  These pens aren't cheap either.  All added up to my saying, abort .... abort... take it to the experts first. 

[CS388]

Very wise. I'm sure many people wished they had exercised such caution, during early repairs.

 

If you get it to that stage again, try dropping some water with washing-up liquid onto the seal (very weak mixture) and see if you can gently coax some movement into it - small moves, up and down and rotations. It may be enough to get it started and, if so, you may get it out.

 

If it remains stubborn, trust your instinct and leave it - until someone comes in with a better idea. You're doing the right thing by not forcing it.

 

Good luck.

[maclink]

An Update:

Success!! 

 

I loosened the piston cap and assembly, and squirted some water with a little soap down the barrel.  The piston popped right out.  It looked pristine.  No gunk or anything.  I washed the barrel out with a syringe, flushing several times, applied a little silicon grease to the piston and put things back together.  We are good to go!! 

 

Thanks for your tips! This was my first MB pen disassembling of any kind.  Been staying away from it. Will muster the courage to do the nib next.

 

Three of my pens are pre-owned and out of warranty.  My other three were bought new and within warranty period but they are working perfectly anyway.

 

Now I'll give this broad nib another run to see if the hard starting issue will go.