Last updated: October 2, 2026
A La Marzocco silicone group gasket is a small, inexpensive part that has a large effect on espresso quality. It seals the portafilter against the group head. When it hardens, flattens, tears or no longer matches the group, water escapes around the basket instead of passing cleanly through the coffee.
Replacing the gasket is usually easier than replacing a portafilter or repairing a leaking valve, but buying the correct version matters. La Marzocco has used different group designs and gasket dimensions across its home and commercial machines. “Fits La Marzocco” is not enough information by itself.
Quick answer: Our top pick in 2026 is the Silicone gasket — our #1 rated choice. See the full ranked comparison, alternatives and buying advice below.
What the group gasket does
The gasket sits in the group head, above the dispersion screen. Tightening the portafilter compresses the gasket and creates a watertight seal. The portafilter handle should normally stop in a consistent position, with enough resistance to hold pressure without requiring excessive force.
A worn gasket can cause:
- Water dripping or spraying around the portafilter during brewing
- A portafilter that rotates unusually far to the right
- Leaks that appear only at higher pump pressure
- Bits of rubber or silicone sticking to the portafilter rim
- A group head that remains wet after the portafilter is removed
A leak is not always caused by the gasket. A damaged portafilter rim, a poorly seated shower screen, coffee buildup in the group, or a loose screen screw can create similar symptoms. Clean the sealing surfaces before ordering parts.
Silicone versus traditional rubber
See also: Best Espresso Knock Boxes: Size, Capacity and Counter Space Compared • Rocket Espresso Cleaning Tablets
Silicone gaskets are popular because they remain flexible for a long time and are less affected by heat than many basic rubber compounds. They also tend to release from the group head more easily during the next replacement. That is useful if you maintain the machine yourself and do not want to scrape out a hardened ring.
Rubber is not automatically inferior. A correctly sized, good-quality rubber gasket can seal well and costs less. Its main disadvantage is that heat and repeated compression can make it hard sooner, particularly on a busy machine. Once hardened, it may leak even though it still looks intact.
| Option | Advantages | Trade-offs | Best suited to |
|---|---|---|---|
| Silicone gasket | Flexible, heat resistant, often easier to remove | Usually costs more; can feel slightly softer during locking | Home users who want longer service life and easier maintenance |
| Rubber gasket | Low cost and widely available | May harden or flatten sooner; removal can be messier | Budget repairs and machines used occasionally |
| Original-equipment gasket | Correct specification when matched to the machine | Can cost more and may not be the best material option | Owners who want the safest fit with a known machine model |
| Third-party gasket | More material and thickness choices, often cheaper | Fit and dimensions vary between brands | Shoppers willing to verify measurements and seller compatibility |
For a lightly used home machine, the cheaper rubber option is often perfectly adequate if it is the correct size. Silicone becomes more compelling when the machine is used daily, the group runs hot, or you expect to keep the machine for many years.
How to choose the correct size
Do not choose solely by machine brand. Check the exact model and, where possible, compare the gasket’s outside diameter, inside diameter and thickness with the part currently installed. The shape of the inner opening and the sealing lip can also matter.
Some La Marzocco machines use a gasket associated with the standard commercial-style group, while other machines or revisions may use a different profile. A gasket that is only slightly too large may be difficult to install. One that is too thin may allow the portafilter to travel too far before sealing. One that is too thick may make locking unusually difficult or prevent the portafilter from reaching its normal position.
If you do not know the measurements, begin with a La Marzocco group gasket replacement search, then check the listing against your exact machine model. Read the compatibility notes rather than relying on the product photograph, since many gaskets look nearly identical.
Replacing the gasket
Turn the machine off, unplug it and let the group cool. Remove the portafilter and shower screen. A flat screwdriver or gasket pick can help lift the old gasket, but protect the group’s metal surfaces. Do not gouge the groove while prying.
Clean away coffee oils and loose gasket material with a soft brush and a damp cloth. The new gasket should sit flat and evenly in the groove. If it has a beveled side or a marked face, follow the manufacturer’s orientation instructions. A small amount of water can help it seat; grease is generally unnecessary and can attract coffee residue.
Reinstall the shower screen and screw, then lock in the portafilter without coffee. Run water briefly and check for leakage. The handle may feel stiff for the first few uses. Do not force it beyond its normal range. If it stops much earlier or much later than before, remove it and check that the gasket is fully seated and the screen is installed correctly.
For removal tools, a group gasket removal tool can be worthwhile if the old gasket is stuck. For a single replacement, a small blunt pick may be enough, but sharp tools make accidental scratches more likely.
Common buying and fitting mistakes
Buying by appearance: Similar-looking gaskets can have different thicknesses. Confirm dimensions and compatibility.
Installing over dirt: Old coffee oils or gasket fragments can hold the new seal out of position. This causes a leak that looks like a bad replacement.
Over-tightening the portafilter: The handle does not need to be forced to a particular angle. Excessive pressure can accelerate gasket deformation and make removal difficult.
Ignoring the portafilter: A nicked or bent portafilter rim can defeat a new gasket. If the replacement leaks immediately and the gasket is seated correctly, inspect the rim.
Waiting for a major leak: A gasket that is beginning to harden can still brew, but a small leak can run down the group and portafilter. Replace it when sealing becomes inconsistent rather than waiting for water to spray.
What to buy
Choose silicone when you use the machine frequently, value easy future servicing, or the price difference is small. Choose rubber when you need an inexpensive repair for an occasional-use machine and can verify the dimensions. Original La Marzocco parts are the conservative choice when compatibility is unclear; a reputable third-party silicone gasket is reasonable when its measurements and model list match.
A silicone espresso group gasket is also a sensible spare to keep with a home maintenance kit. It takes little space, and the machine can become unusable at the worst possible time if the old gasket suddenly splits.
FAQ
How often should a La Marzocco group gasket be replaced?
There is no fixed interval for every machine. Inspect it annually, and replace it when it leaks, hardens, cracks, flattens or allows the portafilter to rotate noticeably farther than usual.
Can I use any 8.5 mm group gasket?
No. Thickness alone does not confirm compatibility. The inner and outer diameters, profile and group design also need to match your machine.
Why does my new gasket still leak?
Check that it is fully seated and that the shower screen is installed correctly. Also inspect for trapped gasket material, coffee buildup, a damaged portafilter rim or a gasket intended for another group.
Is silicone worth the extra cost?
Often, but not always. Silicone suits frequent users and people who service their own machines. For occasional use, a correctly fitted rubber gasket is usually the better-value repair.
Ready to decide? Our #1 pick for 2026 is the Silicone gasket.
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