Gaggia Classic pushes out portafilter during brewing

Need help with equipment usage or want to share your latest discovery?
haarts
Posts: 2
Joined: 8 years ago

#1: Post by haarts »

Hi!

I recently purchased a Gaggia Classic (second hand) and I have been using it for a month or 2 now. All was dandy, it took me a bit to get the grind right and determine how much coffee to use but I've been enjoying great coffee since a month or so.

This morning however I made my morning espresso and during brewing the portafilter came loose! It was just pushed out the machine by the pressure, coffee and muck everywhere. I did nothing unusual, the evening before everything worked fine.

I've cleaned the portafilter and machine and even removed the shower screen and cleaned it. To no effect. What could cause this?

Much appreciate your help!

kidloco
Posts: 244
Joined: 11 years ago

#2: Post by kidloco »

Maybe your group gasket is worn out, vibration cause PF to rotate and PUUUF...

HoldTheOnions
Posts: 764
Joined: 9 years ago

#3: Post by HoldTheOnions »

Probably what kidloco said, but could also be if you got some lube on the gasket then will make it slippery. Could also be you simply aren't putting it in tight enough.

haarts (original poster)
Posts: 2
Joined: 8 years ago

#4: Post by haarts (original poster) »

It does indeed seem that it has something to do with the gasket. It sort of gets pushed out under pressure. I've ordered a new one. Thanks!

User avatar
Calendar
Posts: 72
Joined: 12 years ago

#5: Post by Calendar »

Hi,

I had and have this issue. It is somewhat perplexing. Let me share what I know.

Yes - change the gasket. Both 10mm and 9mm gaskets are sold for the Gaggia Classic - make sure you get the thinner, 9mm one. Also, make sure it is well seated.

I made that change and saw some improvement - but the problem didn't go away.

Next - dose smaller. When my portafilter won't tighten properly AND I'm dosing 18 or more grams in a double basket - the portafilter is at risk of pushing out. I now dose 17 to 17.5 grams, grind finer, and that has made push outs somewhat rare.

Now here is the interesting evidence. The issues seems to have something to do with warping when the machine is on for long periods of time. I know this doesn't make sense, as the group isn't going to warp - but here's some pics.







The top picture was taken yesterday. The machine had been on for 6+ hours. The portafilter is empty, and it is tightened as absolutely far as I could by hand (I'm a big guy).

The bottom picture was taken this morning - the machine is cold, and the portafilter is also empty and tightened as far as possible by hand.

Interesting, no? I'm curious for input from others.

SJM
Posts: 1819
Joined: 17 years ago

#6: Post by SJM »

I am quite sure that the correct depth for a Gaggia Classic with the aluminum/brass boiler group is 8.5 mm. Some of the available gaskets have a bevel on one side; if you source one with the bevel, the bevel goes 'up' -- towards the boiler.

Cerini has one here
https://www.cerinicoffee.com/group-gask ... -machines/

Espressoparts has one here, and they ship parts for free
https://www.espressoparts.com/gaggia-co ... ter-gasket

User avatar
Calendar
Posts: 72
Joined: 12 years ago

#7: Post by Calendar »

Yes -thanks.

I checked my reciepts. I do have an 8.5 in there now. I've also seen 9mm sold for these machines.

When you say the bevel should be up, you mean it should be against the group, not the portafilter?

SJM
Posts: 1819
Joined: 17 years ago

#8: Post by SJM »

Yup....against the group.

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Calendar
Posts: 72
Joined: 12 years ago

#9: Post by Calendar »

Follow up.

My new gasket arrived yesterday. I removed the old one, which yes, was in upside down. Put the new one in correctly, and the portafilter now tightens past perpendicular even after being left on all morning.

Thanks for your help!!

I'd be interested in the thread starter's experience.