The S1 Cafe - Helping Your Espresso Dreams Become Reality

My Mini was leaking water from the group after brewing a shot. After repeated detergent flushes intended to dissolve any coffee "stuff" (I usually do a detergent flush once a month - my routine for many years) failed to fix the problem I took the valve apart and took a few pictures to document the process. This is quite easy to do.

• Unplug the machine
  Remove the cup warmer tray
  Loosen the sides
  Unscrew the front control panel assembly
  Remove the 3-way valve vent piping
  Unscrew the stainless steel 3-way valve from the solenoid (it is not necessary to remove the electrical connection to the solenoid
  Unscrew the 3-way valve from the housing that attaches to the group
  Remove the 4 cap screws that attach the housing to the group

I was expecting to see some scale particles but was surprised to see only a thin film on the valve plug and seat. I gave the wetted parts a hot detergent scrub, rinsed and reassembled it. I worked like a charm. It would only need a small passage for air to backflow from the vent tube to the group which would allow water to drain but I didn't see any obvious culprit.

Attached are some photos showing the process and the parts.