Pasquini Livia 90 high brew pressure and valve leaking

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Febbre
Posts: 22
Joined: 1 year ago

#1: Post by Febbre »

Hello!

I own a Pasquini Livia 90 built in 2003 - restaured thanks to help in this forum!!! (I had to descale, restaure the Ulka pump, reset the high temperature sensor, clean the group head, replace the pressostat and the switch)

The flow seems always too high for the standards (18 to 36 in 30s - I do 18 36 in 15/20s generally), to the point that I need to grind too fine and the coffee is too astringent at that point. I own an Eureka Specialità and I generally grind around 1.5 ticks.

Now, for a more objective measure: a blind portafilter with a pressure gauge which can read max 15bar is not enough for the machine! When mounted and while brewing the pressure shoots over those 15 bar. I had to take apart the Ulka pump and substituted the little bearing ball insnide it as a well as a silicon o ring. Can this pump pump so high now? Does this mean I need to adjust some valve? Whiich one?

At the same time, the threeway valve leaks when brewing wit ha blind basket: I thought this was normal but I read it's not. This makes me think something is leaking... the threeway valve?

Are these two things connected? I read that leaking from the threeway would lead to a lower brew pressure, but I seem to have too high pressure. Where do I start?

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hankbates
Posts: 465
Joined: 13 years ago

#2: Post by hankbates »

I would start with the OPV unit, if it is adjusted closed, it will give the problems you are having (and which I have had). See my recent post /repairs/ad ... ml#p973920,
I was amazed to see the unit I have been using for years had a too high setting, and the one I am now working on was even worse...
They work a lot better with 9-10 bars pressure than 15.
Some people rescue dogs and cats, I like to rescue Livias…

Febbre (original poster)
Posts: 22
Joined: 1 year ago

#3: Post by Febbre (original poster) »

Interesting, thanks Richard. I'll try to adjust the OPV to a lower pressure. I'm waiting for a better ranged gauge, the one I borrowed is capped at 11 bar. I wonder if there's a way to lower the pressure directly on the pump. I read somewhere on the forum that the waste is not supposed to leak from the drain while brewing. It will also lead to a big waste of water. Did you post about the mod for redirecting the pipe that leads to the drain back to the water container?

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hankbates
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#4: Post by hankbates »

You are correct, just disconnect the hose from the tee at the drain and remove the tee .
There's no way I know of to drop the vibe pump pressure other than bleeding water off, it always just follows its performance curve.
Some people rescue dogs and cats, I like to rescue Livias…
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Febbre (original poster)
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Joined: 1 year ago

#5: Post by Febbre (original poster) »

Hello! So, the brewing pressure of my machine is at 14 bar. I identified the OPV and I disassembled it for a clean. It wasn't easy to regulate the OPV as you mention in your post. The sealing rubber/plastic material that coats the screw deteriorated. After adjusting the bolt I screwed it back in place, but now the OPV leaks. Any advice on how to seal this screw? Can I purchase the screw coating/sealing material and apply it myself? I'm not sure what it's called though.

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hankbates
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#6: Post by hankbates »

Later models used an oring at this point under the lock nut (OR GASKET 114 VITON 7496052) Metric size 114.
Since there's only cool water here a special material may not be needed.
I looked up this size in the Livia parts manual found on this site under "resources".

Teflon tape may work just as well....
Some people rescue dogs and cats, I like to rescue Livias…
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austinado16
Posts: 387
Joined: 1 year ago

#7: Post by austinado16 »

Hank, I appreciate your post here, an the previous one, about the Livias being set at too high of a pressure. I'm sure mine is too, so I'll be diving in to test and adjust.

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hankbates
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#8: Post by hankbates »

And I'm ashamed to admit that I have been thinking that it was the grinder.....
When you consider that when the BZ90 was first developed there wasn't a lot of prior experience with "prosumer machines " , it becomes understandable that early BZ99s had a collar instead of a lock nut, which made them much more difficult to even adjust.
Some people rescue dogs and cats, I like to rescue Livias…

Febbre (original poster)
Posts: 22
Joined: 1 year ago

#9: Post by Febbre (original poster) »

So, the teflon tape works just fine. Brew pressure lowered to between 9 and 10 bar. I've not experimented much, but I think I've got another issue. (By the way hankbates, have you documented your mod that redirects the water wasted from of the OPV to the main tank?)

I replaced the original shower screen with an IMS precision shower screen compatible with Rancilio Silvia. The screws of this shower screen stick out and they leave a mark in the puck. Mark aside, I think that causes channeling. I've not been able to find flatter screws. I'm already using a basket which I think is quite big (the 16-20 gr IMS). Not sure I really need a deeper basket.

What's your stand with shower screens? Are you using the original one?

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hankbates
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#10: Post by hankbates »

Here's one of my posts on the OPV recycle routing:
Livia 90 small drip tray fix

Actually, the more experience I have on this subject, the more I think that this part of the original design of the BZ90/99/L90 really missed the mark. It seems that if you are running a Livia with the OPV set at 9bar, and you haven't made the recycle routing mod, you stand a good chance of overflowing the under-designed drip tray in a few good shots.

I should point out if you have the automatic version, with three buttons on a touchpad, the only way you can get the 1cup/2cup buttons to work at all properly, you need to figure a way to route the recycle back into the pump suction, after the flowmeter.

I use a 14g basket from Edesia Espress, a UK seller on eBay, and hardly ever go over 13g. I haven't had any problems with the original type shower screen...
Some people rescue dogs and cats, I like to rescue Livias…