Hi,
Last month I acquired a 1980 Elektra Microcasa A Leva that was essentially stored in a basement for 40 years.
After cleaning it up, doing two passes with descale treatment with some Cafetto LOD Green, replacing the gaskets with newer ones, replace the boiler/grouphead separator, it is now in working condition and gives me decent shots.

However, I still have two issues that start to annoy me :

- The Pressure Stat doesn't seem to work at all. I have to watch the unit boil up and stop manually when it reaches 1.2 bar, else it will keep going on and on. From another topic on this board, I deduced that it would be this switch used on the pressure-stat, but it has this chrome cylinder thing on top of it.
https://www.amazon.ca/Omron-Z-15GQ-B-Ge ... B008L5SBMU



I did tighten one screw that was positive (the one connected to the boiler), and tested continuity between the different parts with a multimeter and everything seems fine. So I wonder if it's just an adjustment thing that I would need to do, and if so, how would I do it with this p-stat?

- As I mentioned, the unit gives me decent shots, even though I'm still learning how to dial in the variables with this unit. However, one constant thing I noticed is that removing the portafilter from the grouphead, there's always 1-1.5mm of water above the puck. Before I panic at the idea that it may be the spring not being strong enough and that I need to replace it (even though it doesn't feel like it's mushy), would anybody know if it's another variable that could cause this?

Thanks!

I would guess you might need to descale the pressurestat and replace its O-rings if it's rebuildable. The switch is really common and a dime a dozen. Once you remove it, it should say on the side what it is. Search "micro switch" and you'll find hundreds. But it's more likely the internal piston is stuck.

I suggest to replacing the old pressurestat with at Mater XP110 pressurestat. That's the standard part on the modern MCALs including my 2017 MCAL.

https://www.espressocare.com/products/i ... tat-mater1

I'm not sure about the water on top of the puck after a shot. Mine are dry. I wait a minute before removing the portafilter so there no remaining pressure. Did you apply silicone grease to the piston gaskets? Does the group head leak water when the piston is at rest?

Yep, I did put grease on both notches and gaskets. When I replaced the gaskets (as they were obviously dry), it was leaking everywhere, but it doesn't now, at all.

Oddly enough, I once left my portafilter for one hour in the grouphead in there, and still had a bit of water. I would expect it to flow through the puck during that time, so that's a weird one. Maybe something that has to do with the suction?
I checked some videos in this forum and looking at the amount of crema the shots have compared to mine (I have 1/10th of them), I'm starting to wonder if it really is the spring being the issue, not pushing all the water out.

For the pressure stat, I did mess around a bit and got it to work, at 1.75. So that's something. However, it doesn't come back on, which clearly indicates that the p-stat/switch is blocked. So I guess de-scaling or replacing it may fix it.

shabax wrote:... - As I mentioned, the unit gives me decent shots, even though I'm still learning how to dial in the variables with this unit. However, one constant thing I noticed is that removing the portafilter from the grouphead, there's always 1-1.5mm of water above the puck. Before I panic at the idea that it may be the spring not being strong enough and that I need to replace it (even though it doesn't feel like it's mushy), would anybody know if it's another variable that could cause this?

Thanks!

Long shot, but lack of a good seal between the piston seals and the cylinder can do exactly that (voice of experience here). In this situation, water on top is caused by air leaking where it shouldn't.This is typically caused by improper installation of the piston seals, but in older/neglected machines, it could also be (besides the seals themselves); build-up on the cylinder bore, or a worn bore, or a worn or corroded finish to the bore. If you run your fingernail in the bore and feel anything "catching," then it is time for further investigation. I'd say that it is usually an improperly installed/torn/folded-over piston seal though.

Replacing the spring is usually fairly easy if needed, e.g., if the existing spring is rusted out. There's the approved procedure which involves replacing a bunch of parts and often making special tools, and the procedure that doesn't replace any parts and doesn't need special tools. (The currently-available replacement spring is thinner than your existing spring.)

Plenty of threads on all of the above.

Good luck!

You may want to check if you piston spring is weak. A spring in good condition will be level with the top of the group head top plate.

Thanks for the tip!
As I was checking some things with the p-stat, I touched the shower screen and it was wet even though the unit was off for 4 hours. I removed the lever/plunger and checked if I could "catch" anything with my fingernail. Nothing, entire grouphead was smooth.
2 things that seemed noteworthy (even though it may be associated with me being unfamiliar with this machine) :
- When I lifted the plunger out of the grouphead, there was some sort of water/air siphoning sound. Which, once again, seemed odd as the last shot was 4 hours ago.
- Most of the grease that I bought with the gaskets seemed to be dark brown/grimy. My guess is that it's ultrafines that went up in there but for something that was completely clear on application, it seemed odd.

2nd point is kinda headscratching for me. I don't think the fines should get up to the upper gasket, right? Would that mean that the lower gasket may be folded upon inserting the entire thing the first time?

Adding a picture in case something looks super obvious.

FYI, Doug's description of how to seat MCaL piston seals is a classic: Piston gasket replacement on Elektra Microcasa a Leva