Well, it may be needed at some point; however, I have had the same piston seals in my machine for the last 10 years with no problem.

A long while back I realized that my upper seal almost never wore out, and started only replacing the bottom seal. After a few years of that I started lubing my seals more regularly, and got a lot more time between replacement. About 10 years ago I started to drop the piston just enough for the lower seal to come out of the group, and lube just the lower seal. After it goes back into the cylinder it lubes the walls, and by extension the upper seal.

Moving forward I found that lubing the seal only takes 2 minutes, and started doing it every time I roasted beans (about every 2 weeks). It was mentioned in a thread that it wasn't necessary to do it that often, so I tested to see how long I could go before I noticed the piston dragging in the cylinder. What I found is that between 4-6 weeks (before my third roast since lubing) I would feel the drag that meant I needed to lube. So, for the last couple of years I've been lubing the lower seal every 4 weeks (2 roasts).

I just did it today, and realized that I hadn't replaced my piston seals in 10 years.

So, the investment of a couple of minutes, and a very small amount of lube every month seems to make the seals go a very long time.

These are the standard La Pavoni seals, not silicone. I have a little bag full of them that I don't know if I'll ever use.

That certainly looks quick and easy - but how exactly do you manage to pull it off ?
I am always having a hard time pushing out the shower screen and the portafilter gasket. Last time I also lubed the PF gasket, hoping for the best, but it didn't come out any easier next time. I have to use waterpump pliers to actually get some meaningful pressure applied to the piston, and it always seems that the shower screen pops out first. Only then can I remove the PF gasket easily. It just doesn't feel right .

lassepavoni wrote:That certainly looks quick and easy - but how exactly do you manage to pull it off ?
I am always having a hard time pushing out the shower screen and the portafilter gasket. Last time I also lubed the PF gasket, hoping for the best, but it didn't come out any easier next time. I have to use waterpump pliers to actually get some meaningful pressure applied to the piston, and it always seems that the shower screen pops out first. Only then can I remove the PF gasket easily. It just doesn't feel right .

Maybe it is easier because I don't wait months to do it. I do remember it being more difficult back when I followed the more traditional maintenance routine.

I start by backing off the jam nut on the piston rod so that the travel of the lever pushes the rod lower. That presses the gasket, and shower screen down. After that it comes out pretty easily. I sometimes have to pull the pin from the lever and press the piston rod down manually, but it comes out as much as I need it to in order to wipe the piston off, clean the shower screen, and add a bit of lube to the cylinder walls (or lower seal).

jtrops wrote:Maybe it is easier because I don't wait months to do it.

That might be it. Since I usually only pull a couple of shots at the weekends, I don't lube the seals every other week - more like every other month, or once a quarter.

At this point I'm doing it about every 4-6 weeks. For a few years I was doing it every 2 weeks along with my roasting schedule. Now it's every 2-3 roasts. If I go to 8 weeks I can feel the drag on the seals when I'm pulling shots.