Where it sits and what it seals

The E61 camshaft (C219900425) runs through the front of the group and out to the brew lever. Two of these seals sit on that shaft, held in place by the cam flange, and their job is to keep brew water inside the group rather than letting it track out along the shaft. They see every heat cycle the group does, and like the portafilter gasket they harden and shrink with age.

The symptom to look for

Water trickling or weeping out around the brew lever where it meets the group, most obvious when you backflush or when the machine is cold, means these seals. A lever that squeaks or feels stiff and dry points the same way. That is a different fault from drips at the portafilter rim, which is the group gasket, or water leaving the drain spout between shots, which is the internal valves. Worth working out which one you have before ordering parts.

Replacing them

This is one of the few E61 repairs you can do without pulling the group apart. Remove the lever, take off the cam flange, slide the old seals off the shaft and fit new ones. Pack them with a food-safe high-temperature lubricant such as Molykote 111 on reassembly, since running the shaft dry is what wears both the seals and the camshaft itself. Since you have the machine cool and the tools out anyway, it is a sensible moment to check the group gasket as well.

Specifications

Fitment

Used across Profitec and ECM machines with an E61 group, including the Profitec Pro 600, and listed under the same number by Rocket Espresso. If your machine is another brand, check the seal against your own parts diagram, as E61 groups come from several Italian suppliers with small variations between them.