Help! Consistently Inconsistent GB/5 - Barista Exchange2024-03-28T11:32:36Zhttps://www.baristaexchange.com/forum/topics/help-consistently-inconsistent?commentId=1688216%3AComment%3A225512&feed=yes&xn_auth=no How often do you change the…tag:www.baristaexchange.com,2012-05-28:1688216:Comment:13859272012-05-28T05:15:35.690ZScotthttps://www.baristaexchange.com/profile/Scott890
<p> How often do you change the baskets, screens and gaskets? Do you change them out all together as is recommended? And do you have more then one set? Could you have mixed and match baskets from different sets? Cause that is the most common cause of inconsistent shots between group heads - a worn basket and a newer basket being used together on a machine. Also the baskets can get a hairline crack at the edge that is almost invisible and will cause the shots to pour fast.…</p>
<p> How often do you change the baskets, screens and gaskets? Do you change them out all together as is recommended? And do you have more then one set? Could you have mixed and match baskets from different sets? Cause that is the most common cause of inconsistent shots between group heads - a worn basket and a newer basket being used together on a machine. Also the baskets can get a hairline crack at the edge that is almost invisible and will cause the shots to pour fast. </p>
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<p>Also, this being a EE/ semi auto, the second most likely cause is a leaking brew/three way valve. Water leaking down the drain during a shot will drop the pressure and affect shot time. Most people don't notice it cause the barista is controlling the volume, not a computer. In an AV the shot volume would end up short - cause it's metered water you are loosing - and is easier to diagnose. Sounds more like your problem to me as you mention wet pucks. </p>
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<p>And yes you can clean out the restricter. In emergencies, where we could NOT take the machine down, we would remove the screen and screw, and blow compressed air back through the group head to clear it out. </p> Hey all... this is a really…tag:www.baristaexchange.com,2012-05-25:1688216:Comment:13852222012-05-25T15:58:42.225ZKeith Eckerthttps://www.baristaexchange.com/profile/KeithE
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<dd><div class="description" id="desc_1688216Comment1384814"><div class="xg_user_generated"><p>Hey all... this is a really interesting thread... I have a similar issue with a 3grp 2007 GB5 AV model... however, the middle and rightmost groups run at the exact same flow rate e.g. reaches required volume in 26 secs whereas the leftmost group runs fast e.g. reaches required volume in 19 secs. This is consistently the case, was thinking if…</p>
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<dd><div class="description" id="desc_1688216Comment1384814"><div class="xg_user_generated"><p>Hey all... this is a really interesting thread... I have a similar issue with a 3grp 2007 GB5 AV model... however, the middle and rightmost groups run at the exact same flow rate e.g. reaches required volume in 26 secs whereas the leftmost group runs fast e.g. reaches required volume in 19 secs. This is consistently the case, was thinking if it was scale it would cause one group only to slow down rather than speed up... wondering if it is still scale buildup why the two slower groups run at the exact same rate.</p>
<p>Any ideas what would cause the one leftmost group to run fast?</p>
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<dd><div class="description" id="desc_1688216Comment1384814"><div class="xg_user_generated"><p></p>
<p>Christopher,</p>
<p>If I were a betting man, I would bet on the gigleur (jig-Lee-air) being restricted. La Marzocco does not recommend cleaning these (.6 mm is hard to clean without accidentally damaging) and recommends replacing the gigleurs on all groups at once. They are only around $12 to $15 bucks, and an integral part flow rate control. IF you want ALL 3 groups to have the same flow rate, replace the gigleurs in each group at the same time. This would also be a great opportunity for a group PM (cleaning, gasket replacement) as the group needs to be opened to access the gigleurs. </p>
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<p>Keith</p>
<p><a href="http://www.VeniaCoffee.com" target="_blank">www.VeniaCoffee.com</a></p>
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</dl> Some great info there thank y…tag:www.baristaexchange.com,2012-05-25:1688216:Comment:13852212012-05-25T15:19:43.080ZChristopherhttps://www.baristaexchange.com/profile/mrchango
<p>Some great info there thank you Brady and Olivier.... many thanks</p>
<p>Some great info there thank you Brady and Olivier.... many thanks</p> had the same probleme look li…tag:www.baristaexchange.com,2012-05-25:1688216:Comment:13850642012-05-25T13:18:08.175Zolivier dutilhttps://www.baristaexchange.com/profile/olivierdutil
<p>had the same probleme look like the ruby gigleur need to be clean</p>
<p><a href="http://www.espressoparts.com/MZ_388" target="_blank">http://www.espressoparts.com/MZ_388</a></p>
<p>good way to see is run time how long does it take to fill up on shot glass on ea group . us the same portafilter no coffee no basket</p>
<p>had the same probleme look like the ruby gigleur need to be clean</p>
<p><a href="http://www.espressoparts.com/MZ_388" target="_blank">http://www.espressoparts.com/MZ_388</a></p>
<p>good way to see is run time how long does it take to fill up on shot glass on ea group . us the same portafilter no coffee no basket</p> Flow rate differences that de…tag:www.baristaexchange.com,2012-05-25:1688216:Comment:13853202012-05-25T12:37:00.749ZBradyhttps://www.baristaexchange.com/profile/Brady
<p>Flow rate differences that develop over time are usually attributable to buildup slowing things down. There's no mechanism that I'm aware of that would serve to make a group flow faster.</p>
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<p>Buildup-related issues develop based on usage. What is the usage pattern of this machine? Oftentimes on a 3 group one group will simply never be used, or in some cases one group is used for most drinks. This will impact buildup rate and differences in flowrate over time.</p>
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<p>My…</p>
<p>Flow rate differences that develop over time are usually attributable to buildup slowing things down. There's no mechanism that I'm aware of that would serve to make a group flow faster.</p>
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<p>Buildup-related issues develop based on usage. What is the usage pattern of this machine? Oftentimes on a 3 group one group will simply never be used, or in some cases one group is used for most drinks. This will impact buildup rate and differences in flowrate over time.</p>
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<p>My guess is that there was a serious flow-related issue with the leftmost jet in the past and only it was replaced. Your tech should really replace all of the jets whenever they do a repair that replaces one, to keep the flow rates matching. Though it may seem like only one group has an issue in reality all of them have slowed somewhat over time - you don't see it because they may just be reduced 25% (for example) compared to 75% on the "problem" one. If you replace the 50% reduced one, suddenly it's running like new and the other group or groups will appear slow. I learned this one the hard way, btw.</p>
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<p>Looking into the service history of this machine will give you more clues.</p> Hey all... this is a really i…tag:www.baristaexchange.com,2012-05-25:1688216:Comment:13848142012-05-25T11:10:23.297ZChristopherhttps://www.baristaexchange.com/profile/mrchango
<p>Hey all... this is a really interesting thread... I have a similar issue with a 3grp 2007 GB5 AV model... however, the middle and rightmost groups run at the exact same flow rate e.g. reaches required volume in 26 secs whereas the leftmost group runs fast e.g. reaches required volume in 19 secs. This is consistently the case, was thinking if it was scale it would cause one group only to slow down rather than speed up... wondering if it is still scale buildup why the two slower groups run at…</p>
<p>Hey all... this is a really interesting thread... I have a similar issue with a 3grp 2007 GB5 AV model... however, the middle and rightmost groups run at the exact same flow rate e.g. reaches required volume in 26 secs whereas the leftmost group runs fast e.g. reaches required volume in 19 secs. This is consistently the case, was thinking if it was scale it would cause one group only to slow down rather than speed up... wondering if it is still scale buildup why the two slower groups run at the exact same rate.</p>
<p>Any ideas what would cause the one leftmost group to run fast?</p>
<p>Thank you very much!</p> Yes. I just got home from wor…tag:www.baristaexchange.com,2009-01-01:1688216:Comment:2746462009-01-01T02:14:29.466ZLita Lopezhttps://www.baristaexchange.com/profile/LitaLopez
Yes. I just got home from working on this machine and the problem has returned, even worse than before! AiAiAi! I had tried your suggested empty portafilter test previously and did so again today. The difference between the groups is unbelievable. So, it looks like replacing the flow restrictor is a necessity. Thanks again!<br />
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<cite>Nick Cho said:…</cite>
Yes. I just got home from working on this machine and the problem has returned, even worse than before! AiAiAi! I had tried your suggested empty portafilter test previously and did so again today. The difference between the groups is unbelievable. So, it looks like replacing the flow restrictor is a necessity. Thanks again!<br />
<br />
<cite>Nick Cho said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent?page=1&commentId=1688216%3AComment%3A274500&x=1#1688216Comment274500"><div><cite>Lita Lopez said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent?page=1&commentId=1688216%3AComment%3A274412&x=1#1688216Comment274412"><div>My technician and I did take the groups apart and discovered blockage in the flow restrictor, which he cleaned out and seems to have corrected the problem, at least in the short term. I have not been on the machine for a couple weeks (been out of town) but will check on it later today. The last time I did use it, however, it did seem to be slowly reverting back again. I'll post an update asap and look forward to the benefits of all your expertise.<br/></div>
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Lita, generally speaking, it usually works better to just replace the flow-restrictors rather than cleaning them out. Scale attracts scale, and by irrigating (trying to poke or scrape out the stuff from) the orfice, it's very easy to mess up the size or shape of the orfice, as well as it's hard to irrigate it properly in the first place.<br/>
<br/>
Good luck, and looking forward to new videos!<br/>
<br/>
Your fan,<br/>
Nick</div>
</blockquote> Lita Lopez said:My technician…tag:www.baristaexchange.com,2008-12-31:1688216:Comment:2745002008-12-31T23:18:36.003ZNick Chohttps://www.baristaexchange.com/profile/NickCho
<cite>Lita Lopez said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent?page=1&commentId=1688216%3AComment%3A274412&x=1#1688216Comment274412"><div>My technician and I did take the groups apart and discovered blockage in the flow restrictor, which he cleaned out and seems to have corrected the problem, at least in the short term. I have not been on the machine for a couple weeks (been out of town) but will check on it later today. The…</div>
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<cite>Lita Lopez said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent?page=1&commentId=1688216%3AComment%3A274412&x=1#1688216Comment274412"><div>My technician and I did take the groups apart and discovered blockage in the flow restrictor, which he cleaned out and seems to have corrected the problem, at least in the short term. I have not been on the machine for a couple weeks (been out of town) but will check on it later today. The last time I did use it, however, it did seem to be slowly reverting back again. I'll post an update asap and look forward to the benefits of all your expertise.<br/></div>
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Lita, generally speaking, it usually works better to just replace the flow-restrictors rather than cleaning them out. Scale attracts scale, and by irrigating (trying to poke or scrape out the stuff from) the orfice, it's very easy to mess up the size or shape of the orfice, as well as it's hard to irrigate it properly in the first place.<br />
<br />
Good luck, and looking forward to new videos!<br />
<br />
Your fan,<br />
Nick Hi Nick et al!
Thanks for al…tag:www.baristaexchange.com,2008-12-31:1688216:Comment:2744122008-12-31T21:33:39.526ZLita Lopezhttps://www.baristaexchange.com/profile/LitaLopez
Hi Nick et al!<br />
<br />
Thanks for all the advice! My technician and I did take the groups apart and discovered blockage in the flow restrictor, which he cleaned out and seems to have corrected the problem, at least in the short term. I have not been on the machine for a couple weeks (been out of town) but will check on it later today. The last time I did use it, however, it did seem to be slowly reverting back again. I'll post an update asap and look forward to the benefits of all your…
Hi Nick et al!<br />
<br />
Thanks for all the advice! My technician and I did take the groups apart and discovered blockage in the flow restrictor, which he cleaned out and seems to have corrected the problem, at least in the short term. I have not been on the machine for a couple weeks (been out of town) but will check on it later today. The last time I did use it, however, it did seem to be slowly reverting back again. I'll post an update asap and look forward to the benefits of all your expertise.<br />
<br />
Nick, thanks for the question about my videos. A couple things have delayed my process, including technical difficulties with editing plus a death in my immediate family this year, which seriously knocked the wind out of me for quite awhile. However, with the Western Regional right around the corner, I am getting fired up and geared up again. I hope to have at least one new installment up sometime this month and more to come after. Thanks for watching and stay tuned!<br />
<br />
<br />
<cite>Nick Cho said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent#1688216Comment242481"><div>Hi Ms. Lita! Haven't seen any videos from you in a while... whassupwitdat?<br/> <br/>
Anyway...<br/>
<br/>
For a two-year-old GB/5 2EE, there are three different possible "flavors" of plumbing that you could have.<br/>
1) old banjo-tube w/external solenoid groups (carry-over from the Linea)<br/>
2) Piero-Caps w/teflon flow-restrictor/gicleur<br/>
3) Piero-Caps w/ruby-tipped flow-restrictor/gicleur<br/>
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On any of these, the problem and solution are pretty much the same, though if you've got a #2 setup, you'd wanna switch-out the flow-restrictors to the #3 ruby-tipped ones. Come to think of it, if you have a #1 setup, you'd wanna upgrade to the Piero-Caps as well (#3 setup).<br/>
<br/>
Simply put, your flow-restrictors, a.k.a. "gicleur" (Frenchie for "jet") are a little screw with a very small hole in it that purposefully plugs up most of the flow, so that when you're brewing coffee, it forces the water pressure on the coffee to build-up much more slowly, which has all sorts of effects on the extraction. Overall, it's pretty much always gonna be an improvement over a non-restricted setup.<br/>
<br/>
The downside to having a heavily restricted flow machine is that when you have a hole, say, with a 0.6mm diameter, it doesn't take very much to mess up the flow through that orfice, be it from a random particle of coffee, scale (calcium) build-up, or from physical damage to the orfice itself.<br/>
<br/>
On the old machines (a.k.a. setup #1 above), the flow-restrictors were little brass screws, which were susceptible to scale buildup.<br/>
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On the #2 setup, people got smart and made them out of Teflon, which doesn't attract scale buildup. The problem was that it was really hard to get a consistent orifice size with such a soft material.<br/>
<br/>
Then they switched to a synthetic ruby-type material for the part with the hole. The "body" of the gicleur is made of metal, but the "tip" is a flat disc of red stuff with a hole in it. Scale-resistant, and easier to make consistent orifice sizes with. Yay!<br/>
<br/>
My guess is that you have a #2 setup from my list above.<br/>
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Test: put an empty portafilter in the group (double spouts with the basket in it but no coffee) and put a couple shot glasses under it. Punch on the group and time how many seconds it takes to fill those glasses. Then do that with your other group. Is it different? That's gonna be a difference between your flow-restrictors.<br/>
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Hope this helps!<br/>
Nick</div>
</blockquote> Bill Warnock said:Really they…tag:www.baristaexchange.com,2008-12-27:1688216:Comment:2700222008-12-27T03:32:48.506ZNick Chohttps://www.baristaexchange.com/profile/NickCho
<cite>Bill Warnock said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent#1688216Comment269977"><div>Really they had old banjo's on gb5's thought they were all piero<br/></div>
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(assuming I understand what you're trying to say)<br />
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Nope. GB/5's had Linea-like banjo tubes for at least the first year, maybe two. Thank God for the Piero caps, eh?
<cite>Bill Warnock said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/help-consistently-inconsistent#1688216Comment269977"><div>Really they had old banjo's on gb5's thought they were all piero<br/></div>
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(assuming I understand what you're trying to say)<br />
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Nope. GB/5's had Linea-like banjo tubes for at least the first year, maybe two. Thank God for the Piero caps, eh?