Portafilter not making a proper seal

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Posts: 16
Joined: 15 years ago

#1: Post by fiddlebanshee »

I have been happily enjoying my Oscar since early December and am getting better at pulling consistent shots and steaming milk. However, lately I've noticed that I have to turn the portafilter much farther to the right to make it tight, and even then there is hot water spraying out of the portafilter while pulling the shot. It's about 50/50- - half of the shots there is no spraying, half of the shots there is. I have experimented with obsessively cleaning off the portafilter as well as the grouphead after each shot to see if that made a difference but it didn't.

In a bad case there may be as much as 1/2 oz of water, in a mild case it is only a few drops.

What can be causing this, other than my inexperience (if the latter is the case, please also let me know what I should do to improve).

Your help is appreciated as always.

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#2: Post by another_jim »

You probably have a damaged group gasket. These are usually good for a couple of years in home use before they get hard and stop sealing, but sometimes they get a tear. Spraying and leaking sounds like it could be that.

They only cost a few bucks, and it's useful to always have a few spares on hand.
Jim Schulman

fiddlebanshee (original poster)
Posts: 16
Joined: 15 years ago

#3: Post by fiddlebanshee (original poster) »

Thanks Jim for your advice. I followed up on it and gave Chris' Coffee a call (the vendor where I bought the Oscar). The technician there thought it was highly unlikely that the seal had gone in three months of buying the machine. He gave two more reasons for the seal not being tight enough:

1. grounds in the ring around the grouphead
2. basket too full of coffee.

If these wouldn't remedy the situation they would replace the gasket, but he encouraged me to try cleaning and using less coffee first.

I had eliminated #1 already before I called him, because that was the first thing I thought when this started happening so I had been religiously cleaning the grouphead and the portafilter before and after each shot. So I took his second idea and adjusted the dose, with a slightly finer grind. Lo and behold -- no more spraying, and perfectly timed shots @25 secs with the flow starting at about 9 secs.

I thought I'd give this update in case there might be other newbies that read this and have the same issue.