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Thread: fixing and then pimping my Bezzera BZ99

  1. #1
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    fixing and then pimping my Bezzera BZ99

    Hi there,

    I have been a long time leecher and this is my first real post so go easy on me when I make the occasional faux pas.

    I bought my lovely Bezzera BZ99 about 5 years from Bazari coffee. It was a reconditioned 15 year old machine and I was in love. It was a fantastic machine to to introduce me to the world of making espresso. Since then it hasn't missed a beat - I have looked after her with regular descales, new seals here and there and a few little bits and pieces.

    However, recently she cut out big time! She would turn on and the element would turn on for less than a second but then one of the relays would trip and cut the power to the heating element. I took her apart and after a day with the multimeter and the wiring diagram (one of the worst set out wiring diagrams I have seen!!!) I nailed the problem to the 'black box'- the brain of the machine. It's about a $300 hit to replace one of these (nearly as much as I paid for the machine) so I took it out and got my multimeter out again. I found the problem component on the PCB was just the 240-24V transformer which I picked up on RS online for $5. Soldered it into the PCB and boom!! My machine was back to life!

    So....now my baby is fixed but would like to take the opportunity to make some upgrades:
    1. Fit an new and more adjustable by-pass valve like this: View topic - Fitted the new Brewtus type OPV to my Bezzera :: Too Much Coffee :: The European Coffee Resource
    2. Fit a boiler and head pressure gauge
    3. A bit of boiler insulation (don't really care about cup warming that much)
    4. General internal clean, replace boiler gaskets, some seals ect..


    Starting with 1:
    I've got the bypass valve but am struggling with thread sizing. I can't seem to find an adapter piece that will go between the old pump outlet and the new by-pass valve, the size and the threads seem odd. Can anyone identify exactly what that is in between the pump and the new by-pass valve? It was called a non-return valve but I didn't have one in my original configuration. Even if someone knew exactly what the thread size and type was on the pump outlet would be great. It doesn't seem to be the 1/4"BSP that would have expected and I can't find specifications for it on line?

    Number 2:
    The boiler gauge is a simple 1/4BSP which threads straight onto a soldered attachment point on the copper pipe between the boiler and the steam arm so that was easy

    I was thinking of putting the head pressure gauge in just after it comes out of the HX? Or would it be better after just before it enters the group head? I was just going to use a T fitting at one of the junctions to fit this.

    I'll put some pictures up soon.

    Many thanks,
    Sam
    Dimal likes this.

  2. #2
    Senior Member Yelta's Avatar
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    G'Day Sam, very informative first post, sounds like you are having a good run with your BZ99, Bezzera certainly make long lasting and reliable machinery.

    You obviously know your way around a PCB, very useful skill to have in this hobby.

    Thanks for an informative first post and welcome to Coffee Snobs.

  3. #3
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    Thanks Yelta,

    it's good fun playing with these old machines.

    From looking at some drawings of other similar pumps used in different Bezzera models I am pretty sure that the outlet from the pump is M12. So now I need to source an M12 female to 1/8"BSP fitting to go between my pump and by-pass.....bunnings was useless so into the interwebs I delve.

  4. #4
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    Will be watching this thread with interest. I plan to do similar mods to my BZ99s.

    Miggt I ask where you sourced the valve/gauges, and how much they set you back?

    Probably best to have the group pressure gauge as close to the group as possible; although there probably won't be much of a pressure drop between the 3-way valve and the group.

  5. #5
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    I got the gauges from commercial link removed per site posting policy ($30 each) and the valve was ordered for me by the guys at Dimattina coffee in WA, I think it was about $20.

    When it comes to getting fittings for these machines does anyone know if these will fit: Fittings - Coffee Parts

    Measuring the threads is difficult too becuase at that that 1/4" size the thread count is so similar for all of the common thread types. I would have assumed that they would just use the standard BSP threads?

    Looking to fit a 'T' fitting between the group head and the HX to mount the gauge to and I need a reducer to go from the pump to the new by-pass valve.

    They aren't that expensive so I may just order them and hope for the best. Good excuse to add some extra goodies.....since I am paying the postage after all
    Last edited by Javaphile; 19th February 2014 at 10:03 PM. Reason: Commercial link(s) removed

  6. #6
    Probably drunk on coffee bodyboardingbum's Avatar
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    @Samm3y - Any updates on this? Have recently brought a Bezz' BZ99S back to life too and am looking to do some similar mods. Particularly with the pressure gauge, and possible OPV.

  7. #7
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    Hi there,
    it has been a long time since I have been able to work on my machine. I have been traveling and trying to finish an engineering degree! Yesterday I got a whole day to get stuck in though and pulled the first shot in a long time! What a huge celebration it was.

    Since my last post I have:
    fitted a new pump
    soldered fittings for the head and pressure gauges
    got my by-pass valve in place
    descaled the boiler

    It was basically just putting all the parts together.
    This is where the boiler gauge comes in:

    And the head gauge (this one is a bit messy but the seal is good):

    the new pump and by-pass valve:

    and here is how it looks at the moment. I definitely need to mount those guages somewhere. I think I will make my own back for it - at the moment I'm pretty sure it is in breach of some OHS standards. While I am still dialing in the by-pass valve I will leave it like that though. Just means that now NO ONE will want to make coffee with my machine apart from me... not so bad.

    At the moment the gauges are working well but the head pressure is a bit slow to respond so I think I will shorten the capillary tube. The reason they have such long ones is to make the reading more stable but with the long length of the HX and tubing after the pump it should be pretty stable.

    edit: thought I would attach a picture of the offending transformer that started this whole thing:
    bodyboardingbum likes this.

  8. #8
    Junior Member Personality_Juice's Avatar
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    Hi Sam,
    Any updates on your Bezzy?
    Love to hear how it turned out!

  9. #9
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    I also have a Bezzera BZ99 that I received as a gift in 1996. The machine is still going strong. Built like a tank. I've replaced the pump and some internals and use it every day. I've adjusted the OPV to deliver 9 bar of pressure (previously it was around 12 bar) using a portafiller pressure gauge. After reading a lot the Bezzera (and Livia 90) forums I understand that the gicleur in the BZ99 is 1.2mm. It is located in the elbow joint just after the 3 way solenoid and before the feed in to the HX in the boiler.

    Does anyone have any experience in changing this to a .6mm or a .8mm to reduce water debit. I believe this would help in the gentle ramp up (pre-infusion) from the vibe pump as well as deliver more flavour in the cup having read many posts about it.

    I am open to others opinion on this matter as I would love to keep my BZ99 (it has tremendous sentimental value). The alternative would be to purchase a Linea Mini and have Rick do a pre-infusion mod.

    Any comments welcome.

    This is my first post after lurking for a very long time. Appreciate reading the forums though.

  10. #10
    Senior Member Yelta's Avatar
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    Quote Originally Posted by GeoffSG View Post
    I also have a Bezzera BZ99 that I received as a gift in 1996. The machine is still going strong. Built like a tank. I've replaced the pump and some internals and use it every day. I've adjusted the OPV to deliver 9 bar of pressure (previously it was around 12 bar) using a portafiller pressure gauge. After reading a lot the Bezzera (and Livia 90) forums I understand that the gicleur in the BZ99 is 1.2mm. It is located in the elbow joint just after the 3 way solenoid and before the feed in to the HX in the boiler.

    Does anyone have any experience in changing this to a .6mm or a .8mm to reduce water debit. I believe this would help in the gentle ramp up (pre-infusion) from the vibe pump as well as deliver more flavour in the cup having read many posts about it.

    I am open to others opinion on this matter as I would love to keep my BZ99 (it has tremendous sentimental value). The alternative would be to purchase a Linea Mini and have Rick do a pre-infusion mod.

    Any comments welcome.

    This is my first post after lurking for a very long time. Appreciate reading the forums though.
    Welcome to Coffee Snobs Geoff, nice to see a first post giving us some insight as to what your up to.

    As others will testify, I don't need any convincing as to the quality and longevity of Bezzera machines.

  11. #11
    Mal Dimal's Avatar
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    Welcome Geoff...

    If you're handy with a small soldering iron, you could block off the original hole using Silver Solder and then re-drill it to what ever size suits. Very small drills like the sizes you mentioned can be obtained from specialist hobby suppliers...

    Mal.

  12. #12
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    Quote Originally Posted by Yelta View Post
    Welcome to Coffee Snobs Geoff, nice to see a first post giving us some insight as to what your up to.

    As others will testify, I don't need any convincing as to the quality and longevity of Bezzera machines.
    Thanks for the warm welcome. I can see that you love your Galatea.

  13. #13
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    Quote Originally Posted by Dimal View Post
    Welcome Geoff...

    If you're handy with a small soldering iron, you could block off the original hole using Silver Solder and then re-drill it to what ever size suits. Very small drills like the sizes you mentioned can be obtained from specialist hobby suppliers...

    Mal.
    Thanks for the welcome. I have found an online website that sells the 0.8mm gicleurs. In fact they also stock a lot of parts for the older Bezzera machines.

    Anyone can PM me of you need the web address.

  14. #14
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    An alternative to the adjustable OPV is to fit a 1/8" needle valve in bypass around the pump (i.e. connect the pump dischage to the pump suction. Like this https://www.instagram.com/p/BP1zUopBW7r/
    Dimal likes this.

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