Group and piston seals
The seals inside the group
La Pavoni's manual says any servicing or repair, apart from normal cleaning and maintenance, must be done by an authorised service centre, and that unauthorised repairs or non-original parts void the warranty. Its service-centre list names none in the UK. The method here is from retailers and owners, as marked.
The piston carries two lip seals. Above it, a rod seal sits under a 20 mm internal circlip and a drilled washer. A plastic liner screws into the group with its own O-ring, and an O-ring seals the group to the boiler.
La Pavoni gives no interval in its documents. Whole Latte Love says "La Pavoni recommends that the gaskets should be replaced every three to five years". Owners change them when the lever goes bumpy, the group drips at rest, or water shows above the piston.
Take the lever and the group off
From iFixit's owner guide and Great Infusions, with sizes from La Pavoni's parts list.
- Unplug and let the machine cool fully. Let the pressure out, take the cap off, and empty the boiler to below the group.
- Undo the two nuts on top of the piston rod, holding one while you turn the other. La Pavoni's lock nut is 14 mm; Great Infusions uses 14 mm for both.
- Push the clips off one end of each lever pin with a plastic tool or small screwdriver, slide the two pins out and lift the lever off.
- Undo the two group bolts (M6 hex head, 10 mm) and take the group off. Keep the O-ring behind it to renew.
- Tap the rod down. The piston pushes the screen and gasket out of the bottom.
- With internal circlip pliers, take out the 20 mm circlip and the washer at the top of the group, then the rod seal.
Reseal and refit
Still the owner and retailer guides. La Pavoni gives no torque for anything here.
- If you are renewing the liner O-ring, screw the plastic liner out and fit the new O-ring (465302). Do not over-tighten it going back.
- Fit the piston seals with their lips towards the pressure: the upper one lip up, the lower one lip down (all sources agree).
- Fit the rod seal flat side up, groove down, then the washer and the circlip.
- Grease the seals with food-safe silicone grease and fold them into the cylinder with a small flat tool.
- Refit the group with a new O-ring (465128). Tighten the bolts snug.
- Refit the lever (the rear hole sits higher) and the nuts, leaving the lower nut some downward play.