Maybe it sounds strange, but since I've started to use RO water, the tight lever problem has gone for me. Group is silky smooth.Probably less harness cause to more substantial coffee oil buildup on the moving parts.

Well, I've just reinstalled the brass valves and cam after a complete clean and polish on a lathe, and added MolyKote 111.
Everything is smoother than ever now, so this is me counting the days until the stiff, squeaky lever returns

I will try not to backflush but instead clean the showerhead maybe twice a week instead.

A few years ago I stopped doing any backflushing without first removing the shower screen, after concluding that it just holds onto fines and oil that the backflush then pushes back into the works.

This is the main reason i love the silicone (Cafelat) portafilter gaskets, which makes removing the shower screen trivial (5 seconds and a chopstick). That way the shower screen can get a bath while the group gets backflushed.

I do still get a notably grittier cam actuation after flushing with puro, but that only lasts a day or two and, in my case, doesn't make any noise

Nunas wrote:At the risk of starting a bun fight , if you use sintered metal puck screens, your group will stay cleaner and the lube will stay put for much longer. Plus, you can cut way back on back flushing.

I am going to try this, thanks Nunas!