Hello,
I have had a PV Lusso for almost 1.5 years mated to a Rancilio Rocky - both were bought new at the same time. This combo has been used daily for that period of time but only a couple of drinks a day. We spent the first 2 months of figuring out how to make consistent espresso, and have been doing so ever since until recently. The most common beans we use are Intelligentsia's BC - generally between 1-2 weeks old. We use 16g of beans per shot - this gave us the most consistent pulls (we do two complete pulls per shot after a 10sec pre-infusion).
Over the last 18 months, I have had to tune the Rocky down two notches to keep the grind fine enough - I attributed this to the wearing of the burrs.
However, over the last couple of weeks, I have actually adjusted the Rocky up 4 notches to keep from choking the PV. Even with this setting, most shots result in dripping rather than streams (the normal up to last the couple of weeks was slow streams) and the volume has dropped from normal. When I remove the PF, there is a lot of water left on the puck - much more than normal.
As for maintenance, I have cleaned the shower screen and oiled the lever pins a few times. For the grinder, I have done nothing.
Where should I start looking? Clean the grinder? Keep adjusting grinder coarser? Seals on the PV? Other?
Thanks.

I dont' know how quickly Rocky burrs wear, or how many pounds you've put through, but could the burrs be so worn you're getting a lot of fines migrating and choking your shots?

If the machine is choking it is probably not poor piston seals. This would allow the lever to return quickly even if no espresso poured, by allowing water back past the seals.

It does sound like a possible grinder issue, unless somehow the piston spring became very weak. I've never heard of that happening. One way to test this idea is to manually push down on the piston using the lever shackle as a pushing point. Be careful not to push too hard though!

Try grinding even coarser - at some point a coarser grind should begin to pour faster even if there are more fines now than there were before.

PC

Oh, and it's possible that the boiler pressure has become lower (the Lusso has a gauge I think). Lower pressure means slower fill time for the group, which can reduce shot volume given the same preinfusion time.

Thanks for everyone's responses.

Last night I took apart the grinder (it was a lot easier than I expected) and I cleaned it out. To me the burrs still feel sharp (I wouldnt want to run my finger across them with much force) but I have zero experience in burr sharpness.

This morning I went up one more notch in grind coarseness with similar results (still almost choking the lever).

My gut tells me it is something with the grinder - it feels exactly when you try out new beans and you have to adjust the grind a notch or two. The difference is the amount of notches I need to adjust - it is way beyond what I have experienced as normal.

So, I am going to try some different beans this weekend to rule out the type of beans.

Thanks.

yeah- the Lusso springs stay strong for a LONG time. I have been using one daily for perhaps 3 years now- still going strong. Most likely the grinder...

Just a quick update - I bought a new bag of beans yesterday and everything seems to be back to normal. I am not sure what was different with those other beans but I wont be buying those again.

Thanks everyone for your help.