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Thread: La Cimbali Junior boiler safety valve and pressure gauge

  1. #1
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    La Cimbali Junior boiler safety valve and pressure gauge

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hey guys, I am posting here to get some more ideas on my pressure gauge

    So my junior (circa 90s) with vibe pump is finally put together


    I plumbed it in and have a couple of other minor issues I am hoping you folks have knowledge of....

    1. The pressure gauge seems to stay at around 0.2 to 0.4 bar. I am able to dispense water from the group head despite this.

    What would need adjusting in this case? From memory the gauge went all the way up to 0.8 or so prior to me taking everything apart....
    -i did NOT take apart the safety valve as it's set to 1.8bar by the factory....
    -can the pressure gauge be taken apart/refurbished? I don't notice any leaks coming from it...

    I think the Pstat is OK as the temperature for hot water and steam come out very hot!



    2. The boiler safety valve seems to hiss quietly and a small bit of steam comes out of the holes circled in red. It's not popping the valve, but is that normal? I'll probably end up replacing it...




    I do hear the p stat clicking on and off.


    I will purchase a replacement boiler safety valve next time I head out to the espresso dealer.


    here's a video of hissing + pstat clicking if it gives any more clues...

    https://vid.me/nzIV


    thanks for reading

  2. #2
    Senior Member artman's Avatar
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    You need to check the accuracy of the gauge. If you haven't adjusted anything then the pressure of the boiler should be the same as before.

    You could temporarily hook up another (known working) pressure gauge to the steam wand via a tube and hose clamps and see what the true pressure of the boiler is.

    The gauge can not be taken apart but if it is scaled up inside you could try descaling it. This worked for me (gauge was tardy in response/sticky). I hooked up a meter or so of hose to the gauge and filled with descale solution and left it for a while, gauge on bottom of hose, hose vertical. Then flushed and repeated. This fixed it.

    Te safety valve should not be hissing. Either you are approaching its set value or it's not sealing properly. Checking the true boiler pressure will narrow down the issue.

    Cheers

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    Agree with artman
    Safety valve shouldn't be passively hissing. When you reach the 1.8 bar point, you will definitely hear it/see steam coming out, and it's usually from the top (you can manually trigger the release by pulling on the pin). Imagine 1.8 bar of steam coming out of a little hole You might have an anti-vac valve attached to your safety valve, and those do hiss when the machine is warming up (normal)
    I would try descaling as artman suggested, get a true reading and see what's what. You may need to replace your safety valve (they're a little stubborn to come out though). And you'll be able to see if you're pstat is turning on/off appropriately once you know what pressure your boiler is running at.

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    Hi there, took a while for me to get this figured out.

    I was able to descale the gauge as per artman's instructions and lo and behold, it works again! I was able to set my sirai pstat to around 1.1 bar at rest according to the pressure gauge.

    The boiler safety valve will be replaced soon, but for now works.


    Here is another issue I am having (keep in mind I never pulled a true shot off this junior since I bought it 1 year ago, as I disassembled it soon after I got it. My previous espresso machine experience was a saeco via venezia).

    Without any portafilter in place, pressing the brew button, hot water comes out from the group head as normal.


    When I packed in some coffee into the PF and tried to pull a shot, water came out of the PF as normal, BUT, there was additional water leaking from the top of the group head between the brass and chromed part (circled in red/blue). The 3 way valve also released some water (almost like when you try to backflush with a blind disk).

    The group gasket is new and OEM la cimbali. I believe it's installed correctly (flat side against the group head).

    When I insert the PF into the group head without any coffee, water flows out of the PF as it should.


    What should I be checking for next? Does the OPV need to be adjusted?

    thanks for all your replies!


    barqy


  5. #5
    Senior Member artman's Avatar
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    That's weird. Looks like your seal isn't sealing. Are you using the conical seal? Looks like everything is pristine so you can rule out crud behind the seal etc.

    It should be sealing fine as long as the collar is mounted square and secure.

    The only time mine used to leak was if the seal got old/hard (not your issue) or if the bypass in the rotary pump jammed and the brew pressure went to 15+ bar. Otherwise I don't see why yours would leak.

    Have you checked your brew pressure?

    Cheers

  6. #6
    Super Moderator Javaphile's Avatar
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    Try flipping your seal around, making sure the grouphead is completely clean and free of any crud.


    Java "Ready.....FLIP!" phile
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    Hi

    Yes it's a conical seal. It look something like this: http://caffeforte.com/media/catalog/...011.gasket.jpg

    The flat side I installed against the group head.

    I am wondering now if I need a gasket spacer............


    I haven't been able to check brew pressure. I believe I would need a PF with blind basket and pressure gauge attached to it. Still need to purchase a gauge


    i'm so close to completing this project, yet so far

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    The only way it can leak water there is if the seal itself is leaking water, either because it is not sealing against the basket or because it is not sitting flat on the group casting.

    Did you remove the chrome collar to replace the group seal? It's almost impossible to clean everything properly and get the new seal fully seated unless you do.
    Javaphile likes this.

  9. #9
    Super Moderator Javaphile's Avatar
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    No need for spacers as the seals are available in different thicknesses. The portafilter should lock in between 5 and 6 o' clock (6 o'clock being straight out from the machine.).

    As MorganGT stated, if you didn't do it you need to remove the chrome collar to replace the gasket. After removing the collar and gasket (Don't damage it!) you need to thoroughly clean the grouphead, being careful not to scratch/damage the grouphead, both where the gasket seals against it as well as the 3 indentations where the 3 bolts from the collar seat in. Clean the end of the bolts as well. Once the gasket is put in place with the flat side up against the grouphead put the collar back on finger tightening the 3 bolts into the indentations in the grouphead making sure they are evenly seated into them before tightening them down with a wrench.

    With all this done using a blind disc/basket there should be no water leaking from anywhere until you turn the pump off at which point water should release out of the 3-way valve's discharge pipe. If water is coming out of the 3-way valve's discharge pipe while the pump is running there's likely debris in the valve preventing it from closing completely or it needs to be rebuilt. If water is coming out between the grouphead and the top of the gasket then there's most likely debris there or the grouphead or gasket has been damaged.


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  10. #10
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    I previously installed the group gasket using the same method you described below.

    The only issue was putting the chrome collar back on, it was extremely tight where I had to 'hammer' around the collar to get it back in place...


    The machine was completely dismantled, descaled, and orings/gaskets replaced prior to assembly. So I doubt there is much debris in around?

    I didn't take apart the OPV when I descaled it though, but i doubt that's the issue?


    Anyhoo, I ran out and bought some parts to make a DIY portafilter pressure gauge. The liquid gauge I had to order online from China, so it will take a while to get here.


    In the meantime, if anyone has more ideas, let me know!

    thanks ton

    really appreciate the replies


    barqy

    PS: once this project is done, i have a simonelli personal 1 (similar to mac 2000) that is waiting to be refurbished as well!

    Quote Originally Posted by Javaphile View Post
    No need for spacers as the seals are available in different thicknesses. The portafilter should lock in between 5 and 6 o' clock (6 o'clock being straight out from the machine.).

    As MorganGT stated, if you didn't do it you need to remove the chrome collar to replace the gasket. After removing the collar and gasket (Don't damage it!) you need to thoroughly clean the grouphead, being careful not to scratch/damage the grouphead, both where the gasket seals against it as well as the 3 indentations where the 3 bolts from the collar seat in. Clean the end of the bolts as well. Once the gasket is put in place with the flat side up against the grouphead put the collar back on finger tightening the 3 bolts into the indentations in the grouphead making sure they are evenly seated into them before tightening them down with a wrench.

    With all this done using a blind disc/basket there should be no water leaking from anywhere until you turn the pump off at which point water should release out of the 3-way valve's discharge pipe. If water is coming out of the 3-way valve's discharge pipe while the pump is running there's likely debris in the valve preventing it from closing completely or it needs to be rebuilt. If water is coming out between the grouphead and the top of the gasket then there's most likely debris there or the grouphead or gasket has been damaged.


    Java "Leaks are bad!" phile

  11. #11
    Senior Member artman's Avatar
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    Quote Originally Posted by barqy View Post

    The only issue was putting the chrome collar back on, it was extremely tight where I had to 'hammer' around the collar to get it back in place...
    Something doesn't sound right there, it could be your issue. If it is not seated /tightened properly as noted in reply above it is likely not to seal properly.

    I would take off and refit. It should go on snug but no hammer needed.

    Cheers

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    Quote Originally Posted by artman View Post
    It should go on snug but no hammer needed.
    Sometimes they do need tapping with a hammer to get them back in place no matter how carefully you've cleaned everything and lined it up again to push it on. Although the method I often use on Cimbalis when the collar needs extra persuasion to be reseated is to use channellock pliers with one jaw hooked over part of the brass casting and the other jaw under the chrome collar to pull the collar up into place, alternating between each of the retaining bolt locations.

    Note: the other VERY important thing to watch for when refitting a Cimbali collar is to make 100% sure the collar is perfectly lined up before tightening the tapered retaining bolts - you should be able to screw them right in with your fingers until the tapered sections of the the bolts seat fully in the holes in the collar, and they should then just require a 1/4 turn or so with a spanner to nip them up tight. It can be hard to get the collar lined up perfectly, and there can be a temptation where the alignment is close enough to get the bolts started in the threads but not spot on, to tighten the bolts down until the tapered sections force the collar into the correct alignment. DO NOT EVER DO THAT - I've seen enough commercial Cimbalis that have had this done when being serviced and eventually it damages the bolt threads or bends (or worse, breaks) the bolts and prevents the collar from being secured in place correctly and securely, leading to leaks. And it's almost always one of the rear side bolts - extracting a broken bolt from there is not fun, and I've had to remove the whole group head (which involves disturbing the HX seal) to remove and repair that kind of damage.

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    Quote Originally Posted by MorganGT View Post
    Sometimes they do need tapping with a hammer to get them back in place no matter how carefully you've cleaned everything and lined it up again to push it on. Although the method I often use on Cimbalis when the collar needs extra persuasion to be reseated is to use channellock pliers with one jaw hooked over part of the brass casting and the other jaw under the chrome collar to pull the collar up into place, alternating between each of the retaining bolt locations.

    Note: the other VERY important thing to watch for when refitting a Cimbali collar is to make 100% sure the collar is perfectly lined up before tightening the tapered retaining bolts - you should be able to screw them right in with your fingers until the tapered sections of the the bolts seat fully in the holes in the collar, and they should then just require a 1/4 turn or so with a spanner to nip them up tight. It can be hard to get the collar lined up perfectly, and there can be a temptation where the alignment is close enough to get the bolts started in the threads but not spot on, to tighten the bolts down until the tapered sections force the collar into the correct alignment. DO NOT EVER DO THAT - I've seen enough commercial Cimbalis that have had this done when being serviced and eventually it damages the bolt threads or bends (or worse, breaks) the bolts and prevents the collar from being secured in place correctly and securely, leading to leaks. And it's almost always one of the rear side bolts - extracting a broken bolt from there is not fun, and I've had to remove the whole group head (which involves disturbing the HX seal) to remove and repair that kind of damage.
    Thanks for tips. I'm working the next 4 days and won't be able to get to it til later.


    I'll try to use a port a filter to to force the seal snug. Right now the handle ptns directly back at me in the 6 o'clock position

    The cimbalis only have one group gasket size right ? I wonder if I was sold right size....although it was purchased from a cimbali dealer they sold me that wrong sized o rings for the group head....

  14. #14
    Super Moderator Javaphile's Avatar
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    Rather than forcing the collar on and risking damage use a green pan scrubber or some really fine wet sandpaper to clean up the inside of the collar and the brass of the grouphead where the collar slides up. It doesn't take much to get it so the collar easily slides on.


    Java "Don't force it!" phile
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    Quote Originally Posted by MorganGT View Post
    Sometimes they do need tapping with a hammer to get them back in place no matter how carefully you've cleaned everything and lined it up again to push it on. Although the method I often use on Cimbalis when the collar needs extra persuasion to be reseated is to use channellock pliers with one jaw hooked over part of the brass casting and the other jaw under the chrome collar to pull the collar up into place, alternating between each of the retaining bolt locations.

    Note: the other VERY important thing to watch for when refitting a Cimbali collar is to make 100% sure the collar is perfectly lined up before tightening the tapered retaining bolts - you should be able to screw them right in with your fingers until the tapered sections of the the bolts seat fully in the holes in the collar, and they should then just require a 1/4 turn or so with a spanner to nip them up tight. It can be hard to get the collar lined up perfectly, and there can be a temptation where the alignment is close enough to get the bolts started in the threads but not spot on, to tighten the bolts down until the tapered sections force the collar into the correct alignment. DO NOT EVER DO THAT - I've seen enough commercial Cimbalis that have had this done when being serviced and eventually it damages the bolt threads or bends (or worse, breaks) the bolts and prevents the collar from being secured in place correctly and securely, leading to leaks. And it's almost always one of the rear side bolts - extracting a broken bolt from there is not fun, and I've had to remove the whole group head (which involves disturbing the HX seal) to remove and repair that kind of damage.

    Sorry for the hiatus, work has been busy and this project had to go on the back burner.

    I bought a separate pressure gauge, but the cimbali PFs I have didn't have the proper threads to screw the gauge on (1/8" i believe) ugh. Right now the stock cimabli pressure gauge reads between ~1.0 to 1.1 or so.


    In a desperate move, I ended up buying another group gasket that was flat on both sides, it seemed to seal better than the conical gasket i got directly from the cimbali dealer, but still there are leaks from the top of the group head as indicated in the picture I posted a few posts up.

    With the cimbali gasket, I placed it flat side up against the group head, re-inserted the chrome collar by pushing and use a C-Clamp with a piece of wood to fit it so that the chrome collar holes lined up with the group head threads, but still it leaks.

    Anyway I bolded your text here, maybe the threads on the group head are stripped? leading to improper chrome collar sealing and hence the leaks from the top of the group head.


    At this point I am not sure if I have exhausted my abilities in fixing this, but I am thinking if I should take it to a professional to get the gasket issue fixed before calling it a loss (not sure if I want to throw another $80 in labor + parts for it though)


    thanks for all your time and ideas folks, great community here.


    edit: with the chrome collar off, i notice that both gaskets don't fit the collar very snugly, there are some marking/nicks within the inner collar. Perhaps I need a wider gasket to make a better seal?
    Last edited by barqy; 13th June 2016 at 08:27 AM.



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