La Pavoni - First day issue resolution - Page 2

#11: Post by **jtrops** » June 29th, 2020, 12:07 pm

The temperature on the outside of the group will be lower than the water temperature in the group. The actual temperature you are looking for will be unique to your machine, thermometer, location of reading, and most importantly: taste. The group does sink heat away from the water, but the water is the thing that is getting cooled by the group, so the group will be cooler than the water fresh out of the boiler.

On my machine I have a thermocouple with a cheap digital thermometer, and my sweet spot is 85-87c. I have my thermocouple attached to the bell of the group with an old portafilter gasket.

To figure out your target temperature start by getting a good shot, and then look at the temperature that is consistently giving you that shot. By doing it this way it doesn't matter if your thermometer is accurate as long as it is consistent. When I changed my thermometer I had some awful shots using the temperature that was great on the old one. I had to start over by following my routine, and in the end I found my target temperature was 5 degrees higher than it had been, but the flavor in the cup is the same. So, I'm sure the actual temperature is the same, but the reading is 5 degrees different.

July 9th, 2020, 12:43 pm

jtrops wrote:I have never had the loose boiler issue, but it seems pretty straightforward to tighten the flange.

The way I lube the bottom seal:
1. take off the locknuts from the top of the piston rod.
2. take off the portafilter
3. use the lever to push the shower screen down making it easier to remove the portafilter gasket that holds it in place.
4. pry out the gasket. I use the needle tool that I use for WDT, but anything small should work as long as you are careful not to mar the gasket.
5. lift the lever, and you can put some Dow 111 on the inside of the cylinder. That may be enough, but if you want to get the seal a bit better...
6. pull the pin that connects the lever fork to the piston rod, and push down on the piston rod from the top until the lower seal is clear of the cylinder.
7. grease up the seal, and push it back into the cylinder.
8. put it all back together.

When I set the piston height I have the shower screen, and portafilter in place. Then I move the lever down all the way until it bottoms out. I back the bottom nut off by about an eighth of a turn, and put the lock nut on until it is snug with the adjustment nut, then I tighten the adjustment nut against the lock nut which for me gets me that eighth turn back so my piston is pretty close to the screen. It is better to have a little gap, than to have it bottom against the screen.

How long does this maintenance take and is there a video for documentation purposes of this? I do not want to mess anything up. But I've seen some LP videos where when they pull the lever up with not much force, the thing flies upwards. I absolutely have to hold the base of the LP to pull the lever up, and even then, it's quite a bit of struggle. I am not going to use it anymore until I get this taken care of. I have plenty of DOW but I have never worked on the machine before and do not want to mess it up.

#13: Post by **RobAnybody** » July 9th, 2020, 2:23 pm

YeetSkeeterson wrote:How long does this maintenance take

I have a slightly different routine but it basically boils down to the same idea. In my hands it takes less than 10 minutes. I prefer doing it when the grouphead is still warm to the touch, it makes it easier to push out the showerscreen.
For a step by step guide:

I start by removing the portafilter, then I remove the pin holding the piston to the arm.

Next I remove both the nuts on the top

Then using a wooden spatula I press the piston down with both my thumbs while my fingers hold the rim of the grouphead and the showerscreen until the piston pushes out the showerscreen.

The showerscreen and o-ring can then be easily removed

You can see the piston sticking out, the lower gasket can be lubricated in this position. The lube will transfer to the upper gasket when you move the lever up and down.
Re-assembly is a matter of pushing the piston back in, and placing showerscreen and o ring.
The o-ring can be pushed into place using a basket first and tightening it by locking in the portafilter.

Re-attach the lever to the piston, feel where it bottoms out and adjust the crown nuts such that the piston stops touching the showerscreen as Jtrops mentioned.
And you're back in business!
Cheers,
Rob

The images are bit upside down apparently I think you get the drift

#14: Post by **jtrops** » July 9th, 2020, 5:37 pm

RobAnybody wrote:I have a slightly different routine but it basically boils down to the same idea.

Yep, that looks pretty similar. I'm a bit surprised that it takes 10 minutes though. How often do you do it? I do mine every couple of weeks (when I roast coffee I lube the piston seals). That way then never get too sticky to make much of a fuss to get the piston down.

July 10th, 2020, 1:38 am

I checked the time while I was doing it for the photos, so I guess it would be a bit faster normally, but then again I also didn't want to put to much time pressure on anyone trying it for the first time.

I tend to lube the seals every other week or so, but since I replaced them they have been a bit more sticky (annoyingly so).
Cheers,
Rob

#16: Post by **ojt** » July 10th, 2020, 2:00 am

Every two weeks is quite often. I lube every 3-4 months or so, maybe even less and it doesn't get hard at all, using Dow / Molykote 111. Some report the Loxeal No 9 lasts even longer.

#17: Post by **guijan12** » July 10th, 2020, 3:38 am

The same here; every 2 - 3 months, with Molycote 111.
And the machine is my daily driver (4 - 6 espressos a day).

July 10th, 2020, 9:03 am

DOW111 is indeed sticky itself if too much is applied.

For those who lubricate everything often, how is the resistance when you raise the lever? Do you have to hold the base down? If so, how hard do you have to pull up on the lever?

Getting the piston down is no problem, it feels pressurized well. But I have a feeling pulling it up is far harder than it's supposed to be. I mean I have to hold the base and use considerable force to get the lever to the top to activate it and get water flowing.

#19: Post by **ojt** » July 10th, 2020, 9:49 am

YeetSkeeterson wrote:For those who lubricate everything often, how is the resistance when you raise the lever? Do you have to hold the base down? If so, how hard do you have to pull up on the lever?

I don't know how much difference there is between mill and pre-mill in this regard but since I changed the gaskets and lubed for the first time (didn't do it immediately on the new machine, which I now regret) I have not had to hold down the base when lifting the lever. I have a millennium model. I don't know if there is something in the manner I lift it or what but I keep the prepared PF in my left hand and lift the lever with the right hand. No problems there whatsoever.

#20: Post by **guijan12** » July 10th, 2020, 10:00 am

YeetSkeeterson wrote:DOW111 is indeed sticky itself if too much is applied.

..... how is the resistance when you raise the lever? Do you have to hold the base down? ....

Pre-mill here and no need at all to hold the base down after lubricating.
I apply a very thin layer only and the piston moves up and down much smoother and easier after the Dow111 has been applied.