Parker Vacumatic Sac Trim Length

[Gedion]

Well, I dissembled it, have the right sac, have talc, and have Vacumatic lubricant. How do I measure

where to trim the sac so it doesn't bang into the breather tube? The pen is standard size. The Pen Repair Book

2nd Ed recommends no more than 30 mm. Is there a way to measure that is pen specific particularly if I change out

the breather tube?

 

Thanks

 

[Glenn Atkins]

~27 - 28mm from the end of the pellet.

 

Glenn

[Ron Z]

The diaphragm should be short enough that it unrolls completely without stretching when the pump is pushed ALL of the way down.

[gweimer1]

The diaphragm should be short enough that it unrolls completely without stretching when the pump is pushed ALL of the way down.

 

I've been using 26.5 mm from the junction to the end, and then I check the movement and extension before putting it on the pen. I extend the pump to check the full range, and then trim again if necessary, to find what you describe. The one thing I like about the vacumatic pump is that you do get a chance to fine tune it before committing to it.

[Gedion]

Thank you all for your help!

[FarmBoy]

Just to clarify, the diaphragm for that pen is the smallest size of the three.