My Yama vac pot always stalls

[BaconFat]

I bought an eight cup Yama vac pot last Dec.  The original upper chamber developed a crack and was replaced.  I never had any stalls with the original, but the replacement will stall out 95% of the time.  It will draw down to the five cup mark, then the tube from the upper chamber will fill with coffee and stop.  I've spent the last month trying to figure out why.  I have given the rubber seal a thorough inspection, both visually and with my finger tips to make sure it's okay.  Unfortunately when I pitched the broken upper chamber the original rubber seal went with it.  One thing that helps some of the time is lubing the flange of the rubber seal and the inside neck of the lower pot.  This doesn't work every time.  I've exhausted all my ideas on this so I'm hoping someone here might have a solution.  I even tried going through the process with plain water and it fully siphoned all the water as you'd expect.

[fffolks]

What kind of filter are you using?

[BaconFat]

Cory rod.  I tried the cloth filter once.

[fffolks]

I use the same set up every day and have only had a few stalls over the years and usually with a darker roast. The fix for me has been to grind a little finer.

[BaconFat]

I'll give that a try.  After this started I adjusted to a slightly coarser grind thinking that would help, but it didn't.

[peter]

I'll give that a try.  After this started I adjusted to a slightly coarser grind thinking that would help, but it didn't.

Aaarrggh...  that sounds so frustrating.

I think when you grind coarser, you also increase the fines, and that may causing some of your stalls.

[BaconFat]

Adjusted my Virtuoso down to the 10 mark from 15 this morning, no change.  It seems like the flange of the rubber seal is too small.  I'm talking like 1mm too small.  With the original, when I placed the upper chamber on there was a slight "whoosh" when it was fully seated.  The replacement doesn't do this.  I think I'm going to see if I can find a rubber o-ring that I can place between the flange and the bottom of the bowl.

[Ascholten]

Im my experience I have found stalls are often caused by small leaks,  check your gasket etc make sure it is squeaky clean and fitting right.  If there are any leaks it sucks in air, hence NOT your coffee back down.

Aaron

[peter]

Have you contacted Yama?  They may have some ideas for you.


Speaking of your Virtuoso...  I have that grinder, and ever year or two the three little tabs on the side of the upper burr carrier bust off.  I can tell when it's happening because the grind gets a bit coarser and more uneven.  It makes me think that maybe your grinder is acting up and contributing to your stalls.

[Joe]

I had stalling problems with my Cory wide mouth and it was always the seal. It doesn't vacuum if there is not a good enough seal. I would bet you have a seal problem. Might be time to either diagnose the seal leak or get a new matched set....

[BaconFat]

I had stalling problems with my Cory wide mouth and it was always the seal. It doesn't vacuum if there is not a good enough seal. I would bet you have a seal problem. Might be time to either diagnose the seal leak or get a new matched set....

It's definitely the seal.  I ended up putting a little dab of bee's wax on the seal before use.  Now most of the time it vacuums the upper bowl pretty well.   Had to make some adjustments to how long I kept the pot on the stove burner to keep the extraction to around 4 minutes.  I would have given up on this thing except I think this is the best method of brewing coffee.

[peter]

Just remember the keep the draw-down as part of your timing for the the extraction.

[Joe]

I had stalling problems with my Cory wide mouth and it was always the seal. It doesn't vacuum if there is not a good enough seal. I would bet you have a seal problem. Might be time to either diagnose the seal leak or get a new matched set....

It's definitely the seal.  I ended up putting a little dab of bee's wax on the seal before use.  Now most of the time it vacuums the upper bowl pretty well.   Had to make some adjustments to how long I kept the pot on the stove burner to keep the extraction to around 4 minutes.  I would have given up on this thing except I think this is the best method of brewing coffee.

I figured, good to hear that was the problem.

[simmich]

Adjusted my Virtuoso down to the 10 mark from 15 this morning, no change.  It seems like the flange of the rubber seal is too small.  I'm talking like 1mm too small.  With the original, when I placed the upper chamber on there was a slight "whoosh" when it was fully seated.  The replacement doesn't do this.  I think I'm going to see if I can find a rubber o-ring that I can place between the flange and the bottom of the bowl.

I had a similar problem with one of my olde Cory vacuum set ups and found a permanent solution that works!

1) spray the original rubber gasket with WD40 until it's soaked
2) place wet gasket into a ziplock bag
3) place into a drawer for 4-7 days
4) re-install gasket if it now feels right, if not repeat 1,2,and 3

I did this over a year ago to a totally messed up antique that we use everyday. Its still working good as new.