Hello.

I got a Sheaffer Snorkel and after cleaning, flushing, etc I find that it only takes a small amount of ink with one filling downstroke, less than a quarter of a regular short international cartridge. I guess the sac might be damaged or some gasket. I have pushed the sac with a tootpick and it is flexible, but don't know what to do next.

Is there any way to know where the problem is? I am thinking about taking it to a repair person here in my city but I would like to know what to ask for (and how much should it cost).

By the way, it writes very, very well..

Good choice getting a Snorkel as they are good reliable pen.
As for your problem.This is a very common problem with the Sheaffer Snorkels,the seal doesnt seal good and needs to be replaced.
Every pen tech can fix this easily for a resonable amount.
Alomst all the snorkels I own had the same problem and after a quick visit with my pen tech they work and write like champs.

Dismount the sac protector/snorkel from the rest of the pen. Put the protector in your mouth, then put the snorkel in water. Blow. If bubbles persist for more than a couple of seconds, it's a sac issue. If there's just a brief jolt of bubbles, then let the pressure off and let it fill. Repeat the process and see how much fluid comes out; it's probably not as much as a Int'l Short, but it should be close.

You can check if it's the o-ring by putting your thumb across the end of the barrel and feeling the pressure changes caused by working the fill tube.

Ron Zorn of http://www.mainstreetpens.com does Snorkel restoration(New Sac, Point Seal, and O-Ring) for $35 dollars.