I'm afraid we might be using gaskets that are too small on the Astoria espresso machine at our shop. The portafilters go way past 90 degrees when they're mounted in the group heads. I started wondering if the gaskets are the wrong size. I'm also concerned that when the portafilter is screwed in, the top of the espresso might be touching the distribution screens... anyone else had this problem?

Views: 758

Reply to This

Replies to This Discussion

I've got a cheapo braun espresso machine (under $300) that does this, but it still seals well. As long as it's sealing and as long as it doesn't become increasingly loose, I doubt it's a problem. I'm not established yet though, so I'd get some other opinions.
Hi Spidey - You can get those head gaskets in various thicknesses. 8mm, 8.5mm, and 9mm for example. As your machine gets more use the ears on the portafilter and the bayonett ring on the machine wear down. You can use different sized gaskets to compensate for this. You can also look at the ears of your portafilters and see how worn they are. You should be able to get the different thickness gaskets from whoever you get your gaskets from. They're very common.

As a side note, generally the biggest culprit for causing the coffee to come into contact with the group screens is overdosing your basket. Load your portafilter like normal, put it in the machine, and then take it back out again. Look for the imprint of the screen. If you see it, put in less coffee.

But... if your portafilter ears are too worn or your gaskets are too thin you will excacerbate the problem.
Agreed with Mike, with a couple of additions.

If you are indeed using the incorrect thickness gasket your headspace (gap between screen and top of puck) will be reduced. If your situation is due to ear wear or bayonet ring wear, this headspace won't be affected.

Astoria machines tend to have lower headspace anyway.

If by some chance your parts supplier doesn't have the thicker gasket, you might have to use a paper shim or two under the gasket... something like this.
Thank you! I think i'll order 9mm gaskets, see if that helps. The paper shim is also a great suggestion. I have a feeling I'll be spending a bit of time on these forums. Great stuff.
paper shims rule.

Mike Sabol said:

But... if your portafilter ears are too worn or your gaskets are too thin you will excacerbate the problem.

Technically, the former wont affect headspace, but the latter definitely will.  If the ears are worn, the distance between the bottom of the ear and the top of the dispersion screen remains the same.  What changes is where the edge of the basket mates with the gasket.  Over-worn ears will combine with an over-worn gasket to start leaking.  If either are over-worn, it's not too bad, only when both show signs of wear are you in trouble.

If any case, the 8.8mm is what works well for my Astoria on the stock PF's.  And the gaskets should be replaced about every 6 mo.s in a hoping shop.  And, the PF shouldn't be cranked.  As they get older, they start to get stiff and small, and it takes more and more energy to seal the basket.  When gaskets are replaced, it's a good idea to remind everyone that they've been cranking too far and too hard on too old gaskets for too long, and that they should relax a bit and be more gentle on the new gaskets.  Cranking on new gaskets 'ages' them faster than any other wear factor.


Reply to Discussion


Barista Exchange Partners

Barista Exchange Friends

Keep Barista Exchange Free

Are you enjoying Barista Exchange? Is it helping you promote your business and helping you network in this great industry? Donate today to keep it free to all members. Supporters can join the "Supporters Group" with a donation. Thanks!

Clicky Web Analytics

© 2023   Created by Matt Milletto.   Powered by

Badges  |  Report an Issue  |  Terms of Service