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Help! Silvia Leaking Grouphead Seal?

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  • #16
    Re: Help! Silvia Leaking Grouphead Seal?

    Originally posted by 332837253D20333B520 link=1327195828/13#13 date=1328007640
    Can you point me to the screw that doesnt leave an impression on silvia shower heads?
    M5x12 C/S machine screw. I have a pile of them PM me with your address and Ill send you a couple.

    The OPV on the Silvia is nicely shown in the thread http://coffeesnobs.com.au/YaBB.pl?num=1326254123 The actual OPV is the screw in bit on the LHS of this. It is pretty cramped, but the mechanism is basically trivial - a spring and (if memory serves correctly) a brass plunger. If it is stuck, disassembly and cleaning might actually fix it. I did take mine apart when I set the pressure, but I cant remember a blind thing about how I did it. I suspect it is pretty straight forward since it doesnt stick in my mind.

    Id be really surprised if it was stuck closed though. Adjusting involves measuring the pressure at the group head. You can make a gauge with a 3/8" BSP Tee screwed into the portafilter - one arm to a gauge and the other to a valve so you can let the 25ml/30secs flow through.. It is bulky and only just fits.

    As a first cut - if you do disassemble the OPV - just count the number of turns and screw it back the same amount. Itll be close!

    Geez - I hope you get this sorted soonish!

    /Kevin

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    • #17
      Re: Help! Silvia Leaking Grouphead Seal?

      Im certainly no expert on the Silvia, however, theres only one OPV and if its working for the hot water supply (via the steam wand) then it should be working for the blind PF too.

      UNLESS of course you have so much leakage from the group head that the OPV is never triggered.

      Try running the HW supply and open the steam wand slowly until the OPV stops flowing. Note the speed at which water is coming out the wand. If thats about how much water is leaking out of the group head with the blind PF in, then the leakage is the problem.

      Ive just checked on mine, and thats a LOT of leakage. If thats what youve got, then theres a major problem (or something really silly).

      Gonzo

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      • #18
        Re: Help! Silvia Leaking Grouphead Seal?

        Im not sure I can quantify the amount of leakage but my shots are filling up at a rate of 70ml/10 seconds after pre infusion.

        Thats a whopping 420ml/minute. :-[

        So my double espresso finishes at about 10seconds... way too short.

        Ill experiment with what youve said but somehow it makes sense, if it works for water, why not the group head.

        Comment


        • #19
          Re: Help! Silvia Leaking Grouphead Seal?

          70ml in 10 secs? Yes thats how much flow is needed to stop the OPV bypassing on my Silvia.

          Methinks you have a leakage problem, not an OPV problem.

          Return to GO.

          Gonzo.

          Comment


          • #20
            Re: Help! Silvia Leaking Grouphead Seal?

            Originally posted by 535B5A4E5B56340 link=1327195828/18#18 date=1328131332
            70ml in 10 secs? Yes thats how much flow is needed to stop the OPV bypassing on my Silvia.

            Methinks you have a leakage problem, not an OPV problem.
            Via the process of elimination - the water feed from the tank goes to the boiler via the OPV. The feed from the boiler to the group doesnt exist - the group is part of the boiler (it is the bottom of the boiler). So unless the bottom of the boiler is leaking, it has to be in the pump-->OPV circuit.

            Or JWLs original observation is correct - it is massively over pressure and leaking around the seal.

            JWL: go to Coffee Parts and have a look at the parts diagram for a Silvia..

            PS: Screws are in the post.

            /Kevin

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            • #21
              Re: Help! Silvia Leaking Grouphead Seal?

              KJM, why cant the leakage in his grouphead be sufficient to not allow the pressure to build enough to trip the OPV?

              Gonzo

              Comment


              • #22
                Re: Help! Silvia Leaking Grouphead Seal?

                Hey Gonzo and KJM, what do you guys think? Im considering buying an adjustable opv to swap out the current unadjustable opv. Even though I dont have a pressure gauge portafilter, my plan is to set it to the lowest pressure and see how I go....

                I really rather it stop pumping out coffee than leaking all over it, then... I can slowly increase the pressure till coffee does come out.

                I researched a little and it looks like the adjustable opv will fit my v1(i think my machine is a 2005 v1) (Old style drip tray, new badge in the front, old steam wand, old opv).

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                • #23
                  Re: Help! Silvia Leaking Grouphead Seal?

                  Forgot to post, thanks for the screws Kevin! Gonzo, Im going to try and underdose to try and see if it doesnt leak as much....

                  Comment


                  • #24
                    Re: Help! Silvia Leaking Grouphead Seal?

                    Originally posted by 6B706F7D65786B630A0 link=1327195828/21#21 date=1328185034
                    I really rather it stop pumping out coffee than leaking all over it, then... I can slowly increase the pressure till coffee does come out.
                    Originally posted by 6B706F7D65786B630A0 link=1327195828/22#22 date=1328186428
                    Gonzo, Im going to try and underdose to try and see if it doesnt leak as much....
                    I thought it was a V2. I think the under-dosing is a good idea to start. When you get an adjustable OPV youll need to get a pressure gauge. Theres one circulating on this forum which you can get to set it up.

                    Gonzo

                    EDIT: heres the link http://coffeesnobs.com.au/YaBB.pl?num=1253305789 Go to the end - its a few pages long.

                    BTW, I still think it sounds like a leak problem not an OPV problem.

                    Comment


                    • #25
                      Re: Help! Silvia Leaking Grouphead Seal?

                      Originally posted by 7F777662777A180 link=1327195828/20#20 date=1328162479
                      KJM, why cant the leakage in his grouphead be sufficient to not allow the pressure to build enough to trip the OPV?
                      Sorry - that was not what I was trying to say. My comment about leakage sources was that the grouphead "mechanism" is actually part of the boiler proper. There is no external plumbing - so unless the O-ring seal on the bottom is cactus, there isnt a source of leakage (modulo cracks and the like).

                      Originally posted by 79627D6F776A7971180 link=1327195828/21#21 date=1328185034
                      Im considering buying an adjustable opv to swap out the current unadjustable opv.
                      If this is a V2 Silvia it is adjustable! The bit with the return hose on it screws in to increase pressure and out to lower it. There is a locknut to maintain the setting.

                      Gee - remote fault diagnosis is interesting!

                      /Kevin
                      PS: Apropos the screws - no worries. I missed the mail bloke yesterday so theyre going to leave work today. Sometimes he comes around early :-?

                      Comment


                      • #26
                        Re: Help! Silvia Leaking Grouphead Seal?

                        Originally posted by 030205480 link=1327195828/24#24 date=1328219582
                        If this is a V2 Silvia it is adjustable!  The bit with the return hose on it screws in to increase pressure and out to lower it.  There is a locknut to maintain the  setting.
                        My machine looks like this one on this video where the guy is doing a washer pressure mod...
                        http://www.youtube.com/watch?v=mlElxFaCbXQ

                        Originally posted by 2F272632272A480 link=1327195828/23#23 date=1328214352
                        I thought it was a V2. I think the under-dosing is a good idea to start. When you get an adjustable OPV youll need to get a pressure gauge. Theres one circulating on this forum which you can get to set it up.
                        I underdosed and found that it doesnt leak as much now but im still getting a heck of a flow rate... It might just be that the pressure isnt building up as much due to the lower dose... Thanks for pointing me to the pressure gauge Gonzo, Ive emailed Greg regarding borrowing it. I think I might start off by grabbing some washers from coffee parts and see how I go with putting them in.

                        I just suddenly had a thought, would scale cause my problem? I havent descaled the machine since I got it (gasp).

                        I think Ill put in the order for some descale supplies and a few washers. Has anyone else done the washer pressure mod? Is there any pitfalls/items I need to watch out for?

                        Right now Im just looking to getting the pressure gauge, the washers and a free saturday afternoon to start taking apart my silvia again.

                        Comment


                        • #27
                          Re: Help! Silvia Leaking Grouphead Seal?

                          Originally posted by 706B74667E637078110 link=1327195828/25#25 date=1328343186
                          I think Ill put in the order for some descale supplies and a few washers. Has anyone else done the washer pressure mod? Is there any pitfalls/items I need to watch out for?

                          Just make sure you measure the pressure at the basket (with Mr Pullmans gear) first.

                          If youre measuring less than 9 bar AND youre leaking around the grouphead, you need to fix the leaking before you do any adjustments on the OPV. The seal should take 9 bar easily. You cant set the OPV correctly if the system is leaking from around the top of the basket.

                          Gonzo

                          Comment


                          • #28
                            Re: Help! Silvia Leaking Grouphead Seal?

                            Originally posted by 677C63716974676F060 link=1327195828/25#25 date=1328343186
                            My machine looks like this one on this video where the guy is doing a washer pressure mod...
                            http://www.youtube.com/watch?v=mlElxFaCbXQ
                            OK - that is a V1 Silvia - you can tell by (for example) the cup tray has a uniform grid of round holes.

                            The OPV in the thread I linked to earlier looks almost the same but youll see it has a locknut. The older style didnt permit pressure adjustment.

                            I still think you need to figure out exactly where it is leaking from. From your dosage reduction you seem to be getting less leakage but watery shots. Which means (to me) that youre getting less than 9bar (way less, Id guess) before you get no leakage. So there is something grossly amiss here.

                            Going back over the whole thing - you initially said there was a "small" leakage. So has this gotten worse? If so - then it must be the new seal install (or indeed the new seal). The OPV might be set a bit high (it typically is a little high), but the primary fault would have to be the seal in this case and as Gonzo said:

                            Originally posted by 6169687C6964060 link=1327195828/26#26 date=1328345921
                            you need to fix the leaking before you do any adjustments on the OPV
                            Of course, if the leakage is coming from somewhere else, then there is a (probably) expensive problem elsewhere..

                            /Kevin

                            Comment


                            • #29
                              Re: Help! Silvia Leaking Grouphead Seal?

                              The early Silvias were made about 10 years ago and some have had a lot of use. At around 7 years I found the PF and group head had worn to the point that while pulling a shot the PF would unlock its self and begin leaking, I solved the problem by carefully dressing the lugs with a fine file to reduce the contact angle.
                              Not suggesting this is the problem, just mentioning it as another thought.

                              Comment


                              • #30
                                Re: Help! Silvia Leaking Grouphead Seal?

                                Thanks for your input Jon, Im going to try and hold the portafilter in place the next time I brew to test your theory out!

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