Parker 51 Vac Repair Problem

[Le Vieux]

A 51 vac ended up on my desk, part of a larger lot purchased sometime ago. Had serious problems with the shellac or whatever adhesive was used to secure the nib section and also the plunger, all solidified and stubborn as well (Pen is inscribed .8. as date goes).

 

Anyways, after heating the plunger part, it opened up, no cracks or deformation of the barrel. First, there is no sign or the old diaphragm, no remnants or bits. Second, although I have had several vacs repaired or diaphragm changed, it is the first time I see this type of plunger: it has no conical part. After unscrewing the plunger, a tube-like part has been left in the barrel. I can see it, but it is not conical so it cannot be the part I miss. Looks like this is cylindrical, and it also seem to be glued inside the barrel. By the color of it, it's made from hard rubber.

 

Can anyone advise, please? I am not familiar with what I am seeing, so perhaps someone can shed light onto what gives here.

 

Many thanks!

 

 

 

 

 

 

[hari317]

looks like someone has fashioned a piston arrangement to act in lieu of the original diaphragm. Filling principle being identical to the vacumatic. i.e. multistroke filler with breather tube.

 

The black part looks like the piston seal and the cylinder in the barrel the bore. If the rubber of the piston head is intact, apply some silicone grease to it and see if it seals well in the bore and slides and retracts without losing suction.

Edited December 6, 2018 by hari317

[Le Vieux]

Right ...never heard of this contraption fashioned on a Vac before. Very ingenious, and rather neat job. So that was the reason no cone and no remnants of old diaphragm were to be found :) . I'll give this thing a go and see if the seal works. If not, I can always tool up some new seal for it.

 

Is this something often seen ? Anyone seen this before?

[Ron Z]

The cone is still in the barrel. The pellet cup is original. Parker used a straight sided pellet cup for a while, which this one has, but you don't see them very often. The cone just stuck to the diaphragm in the barrel, and the pellet cup slipped past when you pulled the pump out.

 

Make sure that you clean off all of the crud on the back of the cone and the inside of the thread bushing., The thread bushing has to spin freely on the back of the cone when you tighten things down. If it doesn't, it will spin the cone, and the end of the diaphragm will get chewed up, which likely will make the pen leak.

[Le Vieux]

Ron, I am afraid the situation is different here.

 

- I started dismantling the pen by first removing the nib section cover. That went well, although a lot of crude and caked, hardened ink and stuff was glued on the inside. The breathing tube needs cleaning, but it's in good shape.

 

- I expected to see remnants of the diaphragm, seeing the pen was obviously not drawing ink when I got it. So I had a glimpse inside, using a light loupe. The inside of the barrel (as I looked from the nib section end of the pen) was completely empty. Upon prodding with a very thin tool, nothing was found, nothing at all.

 

- Then, upon heating the plunger end, I have unscrewed it. I took out the plunger (button, spring and that "straight sided" pellet holder) and had a look inside. Nothing at all. I could see a cylinder glued inside, but that was it. The barrel could be seen inside from one end to the other, and the cylinder inside is completely straight, nothing blocks it. I have checked with a straight wood rod and the diameter of the cylinder (or pipe, whatever) is equal from one end to the other. It measures 4.5 cm, and by the looks of it, it is made from hard rubber (smell and color giveaway).

 

- Now, I am by no means a professional repairer, far from it. Those few Vac 51 pens I have attended so far, none were fitted with a piece of pipe inside. Just the diaphragm, pellet holder and the plunger. No pipes, just the empty barrel.

 

Even if I would fit a diaphragm onto the pellet holder (the hole is there for the pellet to sit), I would have no space inside the barrel to fit the diaphragm, because it will not get inside that blasted pipe. The diaphragm should be inside the barrel, not inside a piece of pipe glued inside the barrel.

 

As things are now, I am forced to fashion some sort of a seal around the pellet pusher, to act as a piston seal inside that pipe. Thing is that the diameter is very small, only some 3mm or so.

 

I hope this all makes sense. Thank you for your input, really appreciated!

[Ron Z]

Come on, give me some credit for the hundreds of Vacs and Vac 51's I've repaired. I can see the metal cone in the end of the barrel. in your picture. You're looking at the butt end of it that fits up inside the thread bushing. I've seen it many times before. That's not a piece of pipe. Its not glued in. When the diaphragm hardens it can act like glue, holding the cone in the barrel against the seat, with the hardened diaphragm stuck between.

 

Put some naphtha on it to soften the rubber, or throw it in an ultrasonic, or soak it over night, and then stick something in there so its a snug fit and warm the barrel while wiggling it a bit - it'll come loose.

[Le Vieux]

Thank you, Ron. Will put into the u/sonic and try to wiggle the darn thing out of the barrel.

[FarmBoy]

As Ron indicated you have not removed all of the filler, the sleeve is stuck to the barrel seat with the old diaphragm.