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Group gasket (portafilter gasket)
Rubber ring sealing the portafilter against the group head — wears flat and leaks; a 6-monthly service item.
Category: Espresso Machine — Groups & Brew Path
The pressure-seal ring fitted in a groove on the underside of the group head. Sometimes called the portafilter gasket because the portafilter clamps directly against it.
Why it matters — This single rubber ring is what holds 9 bar of pressure during every shot. When it goes, you'll feel the portafilter handle position change (it locks deeper into the group) and water will start escaping around the basket.
Good to know
- Common sizes on E61 machines are 8 mm and 8.5 mm thickness — match thickness when replacing.
- A gasket lasts 6–12 months on home use, 3–6 months on café use. Keep a couple of spares.
Related: Group Gaskets