La Pavoni: Lube the piston seals and never replace them again...

[jtrops]

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.

[jtrops (original poster)]

[lassepavoni]

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 .

[jtrops (original poster)]

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).

[lassepavoni]

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.

[jtrops (original poster)]

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.

[lassepavoni]

I'll add this for the record. Just replaced the PF gasket with a fancy orange silicone one. That thing was much too stiff for my liking though (the portafilter would lock pretty tight already after just like 10° clockwise instead of ~50°), so I put the original black rubber gasket back in only two days later. Same hassle of pushing that thing out though. After the shower screen popped out, the gasket was flapping loosely in the group head, so it is not that the gasket alone would be too tight a fit.

[jtrops (original poster)]

First, if your PF wouldn't go past 10°it makes me wonder if you don't have the wrong gasket for your machine. There was a small window around 2008-2009 when they spec'd a thinner 5mm gasket. If you have one of those machines the 5.5mm gasket would cause that lock in issue.

Second, I sometimes have to use a pick to pull the gasket out after I push the piston down to release the shower screen. It's not a big deal, and once it's out the screen drops out like normal. I'm not sure why sometimes it happens, and sometimes it just drops out with the shower screen. After awhile it seems like more it will just drop out more often than not.