I have a seven month old Salvatore Compact Lever machine that is malfunctioning in the following manner: upon releasing the lever after raising it following pre-infusion, the lever "slips," "jumps," or "jerks" upward after encountering the initial resistance of the water in the grouphead. When this occurs, I subsequently observe the volume of that shot to be significantly lower than usual (normal shot volume is around 40-45 gr.; when the lever "slips" on release, shot volume is down to around 25-35 gr.). This problem began to occur after using the machine for about a month, and seems to occur sporadically: sometimes it won't happen for weeks at a time, and then sometimes it will happen every time I pull a shot for days at a time (seemingly regardless of how I try to change grind size or pre-infusion time).

FWIW, I am using an OE Pharos to grind, a 20 g. VST filter basket dosed with 20 g. of coffee, and have the IMS Competition 200 IM shower screen in the grouphead.

Having researched this issue on the forum and after consulting with the manufacturer, I replaced the piston seals with the silicone ones by Cafelat. For the first few weeks after installing the new seals, pulls were normal - no "slipping" or low volume shots. Then, about 5 days ago, it started again, and has happened on every shot since then.

Here is a link to a video that shows the lever "slipping" or "jumping" up: From what I have read, changing the seals works to resolve this issue in some cases and doesn't work in others. To those for whom the piston seal change did not work, have you found the cause of the problem? Has anyone found something else that worked to resolve this issue? Thanks in advance for any insight you can offer!

It could that your grind is too coarse? Water comes rushing out with out resistance it is probably pushing past your seals and causing it too skip. Just an obversation, but that grind seems way too coarse to provide proper resistance.

with a seven month old machine I'd say that the manufacturer is the goto person...seems as if the seals let go, but the water seems to gush through the beans like crazy as if they don't offer much resistance, how old are those beans you're using? Have you tried fresh roasted beans from a good roaster, ground to proper level?

Normally you's expect it to take 5-10 seconds before first drip when doing pre infusion, in your video a stream apppears immediately, and then the espresso gushes out which looks like either very old beans or very gassy very fresj roasted beans not offering much resistance either way.

I do not usually grind this coarse; my thought in going this coarse was that perhaps the water was escaping back past the seals because the coffee puck was providing too much resistance - obviously this turned out to not be the case. When this initially began again several days ago, I had just changed to a new bag of coffee, and the setting on my grinder that had been working well with the previous bag was too fine - shot time was about 55 secs. I incrementally changed the grind to get my shot time down to 25-30 secs, but shot volume was low because the lever was slipping on the way up. So to troubleshoot this, I kept increasing grind size. The shot that you see is as coarse as I went. I'll certainly tighten it up before I try pulling any more shots, but the lever was "slipping" in the same way when the grind was at the correct size.

The beans were freshly roasted from a good local roaster, but I'll pick up a new bag from a shop that sells fresh Verve later today and see if that makes any difference.

The manufacturer is looking into it, but while I'm waiting to hear from him I know that there is a ton of experience and expertise on this forum, so I thought I'd poll you all as well.

You likely have either a piston or sleeve out of spec. As long as you have your seals placed appropriately, and are still having issues, you'll likely need to add some teflon wraps underneath the seals to bulk them out a bit to create a better seal.

I do not have my lever machine yet, still waiting patiently. But if my pump machine would begin to flow through the portafilter that quickly, I would be making the grind finer. Also if the flow is appearing that soon it may be that the chamber above the puck is not getting enough time to fill with water due to the coarseness of the coffee grind before the handle is raised retaining some air below the seals. When I was still employed in the food industry, I maintained a machine that filled one pound tubs of cake frosting. If the pump chamber on that machine did not get a full fill the reaction on the air cylinder that drove the pump was quite similar. But take this advice with a whole handful of salt as I am not even a rank amateur as of this time regarding lever espresso machines.

I there a possibility that a seal is backwards? I had that happen when I was on vacation one time and the frosting pump had been serviced by another guy that wasn't paying attention when he reinstalled the seals. We all get distracted at times. Certainly not saying this is the case but I would check and relube while there to see if that made any difference also.

TomC wrote:You likely have either a piston or sleeve out of spec. As long as you have your seals placed appropriately, and are still having issues, you'll likely need to add some teflon wraps underneath the seals to bulk them out a bit to create a better seal.

Plus 1 on that, if your beans and grind are ok that would be my best guess also...back to the manufacturer I guess, which is a hassle anyone would like to avoid but from afar it seems best to have them sort it.

No expert here, a couple of things I tried with the Salvatore lever. Have you tried using the standard basket with 15-16g of coffee? Also you can try easing the lever back till it engages, and then there's the double pull which can create a bit of mess. I ended up following Cecil and removing the inner spring. It's a somewhat complicated process and mine is squeaking more than it did before, maybe the spring is rubbing.

I lube the cylinder wall all the way around with a thin coat and try not to gob the piston with Dow Molykote.

Just speculating here and I might be terribly mistaken. Could it be a systematic design limitation on the modern 58mm lever group in general, considering the lever slipping/not-catching is also a not-uncommon issue with Londinium? And that there was a need to redesign some new piston seals to prevent that?

When I was playing with a Londinium (uses similar group), I found that the piston assembly just slips right out of the bore with minimal/no resistance, suggesting a much smaller piston+seal OD than the bore ID. Whereas on my Aurora lever, the piston has to be gently wiggled out/in. On Cremina and La Pavoni, the piston & bore fit are also very tight fitting, often require some force to fit the piston in.

Thanks for all the thoughts and suggestions! After dinner this evening I pulled the piston out of the group; I was surprised to find that it was more difficult to remove this time than it was when I removed it the first time to replace the seals. When replacing the seals with the Cafelat silicone seals, I utilized the Molycote 111 lubricant as per the video that Cafelat posted on YouTube. It seemed that the lubricant was very sticky when I removed the piston - in fact there was some residue on the inside of the cylinder that looked like adhesive residue from a price tag. It cleaned away quite easily with a soapy sponge.

I inspected the seals and neither saw nor felt any apparent defects. I cleaned the piston, seals and cylinder walls (just dish soap and hot water since it was more thoroughly cleaned just 3 or 4 weeks ago when the seals were replaced). I then replaced the top of the group; the piston seems to fit into the cylinder snuggly - it does not appear to be a loose fit. I am reheating the machine now, and will pull a couple of shots tomorrow morning with Verve Street Level that I purchased today. Fingers crossed - I'll report my findings.

Thanks again for all inputs - I'll continue to take anything you've got!