Lever multiple pull techniques - Page 8

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HB (original poster)
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#71: Post by HB (original poster) »

peacecup wrote:I wanted to be sure that no one damaged their machine assuming that since I have not seen grounds in the group during multiple pulls, they would have the same results.
Damage what? :?

Even if a few errant grounds made it past the dispersion screen into the piston chamber, they aren't going far. The rising piston will create an air space with a smidgen of coffee grounds at the bottom; the piston reaches the fill hole; the chamber fills with water. Next the water pushes the grounds back out through the dispersion screen. End of story.
Dan Kehn

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RapidCoffee
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#72: Post by RapidCoffee »

cannonfodder wrote:Here is a little trick I have been using lately...
Normally you have to let the machine sit for a moment or two so it can depressurize...
So if you are in a hurry and need to pull a second shot in rapid sequence, try raising the piston about half a stroke and unlock your portafilter, but please be cautious just in case.
I'm sure Dave discovered this technique on his own. But for the record, I was rereading Mark Prince's La Pavoni Professional First Look! and came across this familiar-sounding tidbit:
Because of the manual nature of this machine, you do suffer the dreaded "portafilter sneeze" if you try to remove the PF too soon after pulling a shot. There is a trick to minimize it - lift the lever about 3/4 of the way to relieve some pressure inside the portafilter and grouphead.
The article was posted March 13, 2002.
John

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stsmytherie

#73: Post by stsmytherie »

HB wrote:Damage what? :?

Even if a few errant grounds made it past the dispersion screen into the piston chamber, they aren't going far. The rising piston will create an air space with a smidgen of coffee grounds at the bottom; the piston reaches the fill hole; the chamber fills with water. Next the water pushes the grounds back out through the dispersion screen. End of story.
Actually, the dispersion screen -- at least the one on my recently acquired vintage Sama Export a cousin (twin?) of the PV -- has some indentations on the inner surface that can and do trap particles directly around the holes in the screen. Over time, these particles can build up sufficiently to block holes in the screen. This suggests that it may be easier to pull grounds in than to flush out. You'd have to remove the screen and scrub occasionally to monitor this. Not convenient or a lot of fun.

Granted, how long it takes to block the dispersion screen beyond usefulness is open to debate. But my Export suffered from this buildup of grounds on the inside of the dispersion screen. Took lots of scrubbing and a fine needle to correct. Perhaps more frequent preventive maintenance on the part of the previous owner would have helped.

YMMV

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mogogear

#74: Post by mogogear »

I do use the following to help keep the bottom of the piston bore clean in my levers:

Starting with a machine up to temp:
  1. Fill a old margarine tub with a tsp of Caffiza or equal. add boiling water
  2. Remove PF
  3. Immerse the bottom of the group in the foaming cleaner solution. Either raise the manual lever or pull down the spring lever to draw the solution in through the screen.
  4. Hold what you have for a while and expel.
    NOTE: You can replace water in the tub with clean to do a rinse cycle also
Careful not to draw piston up so far as to admit solution bits in to the inlet from the boiler. Just to be safe!

Repeat as needed. I believe that this can also diminish the lube on the piston seals so YMMV.
greg moore

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HB (original poster)
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#75: Post by HB (original poster) »

stsmytherie wrote:Perhaps more frequent preventive maintenance on the part of the previous owner would have helped.
It doesn't take a lot of effort to keep an espresso machine clean. I've seen a smidgen of grounds behind the dispersion screen of the equipment I've used and maintained, but Steve's Restoration of an Olympia Cremina demonstrates there's plenty of cleanliness slackers out there:
srobinson wrote:Job 5, Cleaning the Dispersion Screen

For those of you thinking that my morning went smoothly, let me tell you a little secret: "The Coffee Gods have a nasty sense of humor". Fresh from a string of good luck with the group head, I started to clean the silly little dispersion screen. Tried scrubbing, tried cleaner, tried straight dishwashing detergent, tried toothbrushes, tried scrub bushes...none would work. What was lodged into every little machined hole of Swiss Miss' dispersion screen was the equivalent of petrified black tar. The only way I could get it out was to use a sewing needle and work each hole.

Image

My 5 minute job resulted in being the longest task of the day taking over one hour to complete. Had I been on Monster House, I would not be leaving with the Makita tool kit or welder. But, on the bright side the group head is completely apart, usable and now ready for rechroming.
mogogear wrote:I do use the following to help keep the bottom of the piston bore clean in my levers:
Interesting. For the Lusso, I flush the group frequently and pop the dispersion whenever the mood strikes me. It's always been clean, but I keep doing it anyway, just in case there's oil buildup.
Dan Kehn

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mogogear

#76: Post by mogogear »

Good observations Dan
You do have to assume that if not much makes it through the holes in the basket that the screen would be equally as effective in preventing upward movement.

I only draw/flush my levers about 1-2 times a year. So I don't over do it for sure. I am a little leery of popping the screen off a lot since they are not super available.

I am with you though my cleaning most likely is not really needed even the old Creminas I first rebuilt didn't have any crazy build up in the cylinders and the screens were no less than 90 percent open. Mostly blocked at a few edge holes.

I am a slacker about really deep cleaning the grinder out----- no vacuum here..............just brush and clack, clack clack! There I said it- flog me! :oops:
greg moore

Leverwright
LMWDP #067

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narc

#77: Post by narc »

mogogear wrote: I only draw/flush my levers about 1-2 times a year. So I don't over do it for sure. I am a little leery of popping the screen off a lot since they are not super available.


Placed an order with Vaneli's for some Ponte Vecchio Lusso spare parts. Not sure what their inventory level is. Last I checked with 1st-Line they had not yet stocked any spare parts. They are the only two on-line retailer of Ponte Vecchios I know of.
LMWDP #151