Rubber shim LF L1190002

A rubber shim creates the seal between an espresso machine's group head and the portafilter. When the portafilter is locked in place, the shim compresses slightly, preventing water from leaking around the edges and ensuring the full pump pressure reaches the coffee puck. Without this seal, pressure drops, extraction weakens and the shot runs unevenly. The shim's thickness and resilience determine how tightly the portafilter seats; too thin and the seal fails, too thick and the portafilter will not lock at all.

To use the shim, first remove the old one from the group head or portafilter rim. Clean the seating surface thoroughly to remove any coffee oils or scale. Place the new shim into the groove, ensuring it lies flat and does not twist or bunch. Reattach the portafilter and run a short flush to check for leaks. If water escapes, the shim may be misaligned or damaged; remove it, inspect and refit.

The shim is cut from 1 mm EPDM rubber, a synthetic elastomer chosen for its resistance to heat, water and coffee oils. EPDM remains flexible across the temperature range of a working espresso machine and does not harden or crack over time. The disc measures 73 mm in outer diameter and 59 mm in inner diameter, matching the standard group-head dimensions used by the listed brands.

This single specification—thickness—sets the compression and therefore the pressure seal. A 1 mm shim is the standard thickness for most commercial espresso machines; it provides enough compression to seal without over-tightening the portafilter. The diameter ensures full coverage of the group-head rim, preventing leaks at any point around the circumference.

Cleaning is straightforward: wipe the shim with a damp cloth after each service to remove coffee residue. Avoid solvents or abrasive pads, as these can degrade the rubber. Inspect the shim weekly for cuts, thinning or hardening; replace it as soon as the seal becomes unreliable.

The shim is a direct replacement part and fits the specific espresso machine models listed in the catalogue. It is stocked under the spare-parts category for espresso equipment, where it is grouped with gaskets, shower screens and dispersion plates.