Hey guys

I bought myself a used Pavoni Professional yesterday and i have been trying to get it running again. The power switch was broken, but i already ordered a replacement for that. The problem is that when i look into the group, the hole that the water is suppose to enter the group from isn't anywhere near the spot where the copper tube is screwed on. It looks like the teflon sleeve has been turned too far and move the opening, is that possible?
If that is the case it might explain why the hole isn't visible when i put the piston in. No gaskets or anything, just dropping the piston into the group and it completely covers the hole. I haven't worked with a Pavoni before, but i assume that the water inlet hole should be clear when the piston is in the highest position?

I might not have done all the homework on the Pavoni. I found this diagram, which clearly shows that the water inlet hole isn't in line of the copper tube. While mine ins't exactly across but more 90 degrees, according to this diagram that shouldn't really make a difference?
http://www.linz.wright.name/pavoni/Pavo ... ection.png

The piston sleeves can seem like they're not fully turned in, when they are. Stefano sells a part (you can check on European La Pavoni dealers too) so you can check that. Essentially it's a square bit of metal that fits in the groove. The main thing is to make sure the piston seals and other group seals are functioning well, assemble the machine and see if it works.

Well my fears turned out to be true. I assembled the entire machine, descaled it and got it up and running, everything seemed fine until i raised the lever and...nothing happened. I could feel the machine try to push the piston back down, so the water must be above the piston, but it never got any further. If I really force the lever up I can hear a bit of steam getting through and see a bit of water droplets under the group, but that's it. Anyone have any experience with this kind of issue?

It is normal that the piston obscures the inlet hole when it's in the cylinder and at its topmost point. The inlet hole is supposed to be near the lower edge of the lower seal when the piston is fully raised.

The most common cause of this problem is that the piston has unscrewed on the piston shaft. Is especially common with the plastic pistons.

In theory, if the sleeve were screwed in too far, that would cause the inlet hole to be too high and might cause your observed problem. Normally the inlet hole is on the front of the group (opposite the neck) when the sleeve is fully in, but there is some variability there.

Another possible cause is a crack in the siphon tube or a poor fit where it screws into the insert.

Make sure you didn't install the lever upside down. The front lever pin should be lower than the center of the fork - should look like this:

(An upside-down lever should not cause this problem, but I seem to recall one instance on this forum where a user claimed that it did.)

The lever isn't upside down, so that can't be the problem. Perhaps the sleeve is screwed too far, i loosened it a bit earlier, but it might not have been enough. I also unscrewed the piston and checked if there was some scale buildup. I found a small amount but removing this didn't solve anything. I have ordered a brass piston since i have read a lot about how the plastic ones are the cause of many problems, and i would rather just avoid any future headaches if possible. Hopefully a new piston will fix this, otherwise i'm running out of ideas.

The sleeve needs to be screwed in snug, otherwise it will leak around the seal. Make sure you have the o-ring in the right place. (see La Pavoni EPC-8 Millenium / Gen III Leaking Through New Sleeve / O Ring )

To get that piston nice and tight on the piston rod you need to stick something through the piston rod hole (phillips screwdriver works good for this) to hold the rod while you grasp the piston with your hand and torque it on tightly. The unscrewed piston is the usual cause of your symptom in machines with a plastic piston.

CoffeeBeetle wrote:I also unscrewed the piston and checked if there was some scale buildup.

Did you unscrew the sleeve and look for scale buildup that might block input? This would be rare and unlikely, but there was one report on CG a while back where a single blob of scale inside the group was blocking flow into the inlet channel of the plastic sleeve:


(Image from https://www.coffeegeek.com/forums/espre ... sso/562639 )

The sleeve is snug no problem there. There isn't any signs of leakage from the sleeve o ring. I have skrewed the plastic piston on as hard as i could and there still isn't any water running through the group. I also checked the sleeve and the inlet hole is clear.
I tried dropping the piston into the sleeve without any gaskets or anything, and the water inlet hole is STILL covered! So the only possible explanation that i see are that either the piston has swollen up, or the sleeve has gotten shorter?? Should have just bought one without all this plastic...

CoffeeBeetle wrote:I tried dropping the piston into the sleeve without any gaskets or anything, and the water inlet hole is STILL covered!

I'll repeat what I said earlier -- The hole is supposed to be covered by the piston. When the piston is all the way up, the bottom face of the piston should be 5-6 mm below the inlet hole, covering it. Note that the piston's lower seal is about 7mm above the lower face of the piston, so when the piston is fully raised the inlet is a mm or two below the lower edge of that seal, allowing water to flow in, spraying against the lower edge of the piston.

It is perplexing that everything seems to be checking out OK with respect to what might be causing your no-flow. Be sure your siphon tube has no cracks and that it and the plastic insert fit the group neck with a good seal. Maker sure that when you raise the lever all the way up that the piston is fully up as far as it will go (guessing maybe if the pins, bushing, fork holes, or group slot were badly worn maybe the lever yoke would hit the topnuts before the piston was fully raised - grasping a little at straws here.)

Didn't notice that the piston should still be covering the inlet hole when everything works properly, now the problem with the piston doesn't seem that severe. Well, about the worn parts. The 2 lever pins are very badly worn, so much that i think it they were meant to look like they do. Both of them kinda look like this:
http://www.francescoceccarelli.eu/La_Pa ... i/pins.jpg


Looking online i see that this might in fact be that my pins are very worn, never considered that until now.