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How to Change Seals: The Ponte Vecchio Lusso Way!

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  • How to Change Seals: The Ponte Vecchio Lusso Way!

    Ok- many have wondered how to change the seals on their Ponte Vecchio Lusso and Export espresso machines. In different countries countless methods have evolved. Some ingenious others brutally affective.  Until now none has been perfect...

    I have finally learned how to do it The Ponte Vecchio Way with a special factory tool direct from PV in Italy.

    Now I understand that saying about having the right tool for the job. Man o man- it is actually fun. I have never loved a specialty tool so much before...

    Here is a photo guide to using the PV tool. It is a simple device- made out of a modified Portafilter handle. A threaded brass rod runs through the PF and is guided by a nut that is welded into the base of the PF.

    There is a turned alloy sleeve to ensure that the seals are held tightly in place as the piston is re-inserted. There is also an alloy plate that guides the filter plate back into place when you are done. Bellisimo!

    So here we go- here is the tool and the two alloy accessories:






  • #2
    Re: How to Change Seals: The Ponte Vecchio Lusso Way!

    Before we start: if you are replacing seals after a period of long use, now is a good time to do a descale and clean of your machine.

    I have found descaling the machine can make the seals in pistons feel squeaky, I think it removes some (or all) of the lubricant, and it can even lead to a small drip leak from a group. As we are going to replace and lubricate the Seals anyway we should Do this Job Now....


    Where I live the water is hard so I mixed three teaspoons of citric acid powder with 3 liters of water and completely filled the boiler. I let is sit for 20 minutes and then turned the machine on. As it came up to heat I blasted water out of the steam arm (when completely filled water comes out of the steam arm) into a milk jug. I then blasted steam through the boiling citric water in the jug to thouroughly blast out and clean the steam nozzle tip. After doing this I blasted water through both groups and the hot water arm also into a metal frothing jug. I ran most of the solution in the machine out like this.

    I let the machine cool, filled with plain water and drained the boiler using a hose to syphon it out of the top water fill hole. I did this twice to completely rinse out any citric acid taste.

    (For a machine with really heavy use you may want to use a commercial descaler or repeat the citric acid flush a few times.)

    Ok -my machine is fresh and clean- just how I like it- the sight glass looks perfectly clear again. Time to switch over those seals.

    First we need to remove the shower screen.

    Do this with a flat head screw driver. On the side of the screen there is a small indentation. Brace the driver against the bayonet of the group and pry the filter off. Dont be afraid: it is clipped on and will pop off. Dont scrape around at the top edge of the plate: catch the driver on the ridge like so:

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    • #3
      Re: How to Change Seals: The Ponte Vecchio Lusso Way!

      The next step is to raise the piston a few millimeters to remove the tension on the pin that holds the lever mechanism together. Too simple: clamp the PF tool in place and tighten the hand screw a few turns. The central piston rod will raise up. Only a few millimeters are necessary.

      Once this is done you need to remove the little c clip on the pin that connects the lever with the piston rod. You can use two flat head drivers to do this- push the edges of the clip in opposite directions. Take care: it wants to fly off and get lost in a crack on the floor. Dont allow it to do that...

      If it does you can find a suitable clip easily at a hardware store. When you come to replacing the clip you can bend it back to shape a little first and then use needle nose pliers to push it all way back into shape once it is on the machine.

      With the clip removed and the piston raised a touch you can safely remove the pin. Take Note: you dont need to undo the other pin that holds the roller. Also note that that the roller pin is positioned on the bottom half of the lever shoulder. Remember to position the lever this way up when you put everything back together. It is easy to miss:





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      • #4
        Re: How to Change Seals: The Ponte Vecchio Lusso Way!

        The next step is laughably easy: simply unwind the hand screw on the PF tool to extension the spring and effortlessly remove the piston:





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        • #5
          Re: How to Change Seals: The Ponte Vecchio Lusso Way!

          Here are the old seals: they look 100% like new: perfect. But they are not perfect. These seals are defective. They are on their way to a bin!

          Ok seal changing time. Use a blunt screw driver or similar tool (take care never to stab, or damage the seals) slide it behind the flat back edge of a seal, pry up, around the back, and pass the driver through the other side creating a gap and stretching the seal. Use your thumbs to work the seal off working around as you go starting at your gap. This should be easy- dont be afraid- use both thumbs. Remove all three- removing the seal at the top last- pull it off the side it is on- over the piston rod. When you do the middle seal pry it right out over the end of the piston. They do have some stretch. You can get a feel for the seals at this time- these ones will be discarded and it doesnt matter if they are damaged. When you install the new ones you must take extra care





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          • #6
            Re: How to Change Seals: The Ponte Vecchio Lusso Way!

            now for the new seals. You will want some food grade lubricant. I recommend a silicon based product like the one pictured here. One tube will last a thousand years at a guess... Dow 101 is similar and also works fine. You dont need much! just enough to coat surfaces. Two match heads per seal... no more.

            It is important to lubricate the seals on the inside edges that are in contact with the piston. You can see each seal sits in a groove where two flat faces of the piston are in contact with two faces of the seal. Each seal has a V section. The top and bottom seal Vs point upwards. The middle seals V points down (be sure to get this right- you can tell the right way by looking at the grooves in the pistons. The flat faces match the flat faces on the seals). Place a little lubricant in each groove on the brass piston. Rub some more on the faces of each seal.

            Start with the bottom seal- push one edge of the seal into the groove as it should sit- then using both thumbs push more of that edge in working your way around. The seal may want to buckle or twist but once it goes over the edge and into the groove it is easy to work it into position. It is similar to changing a tyre on a bike. To help you can soak the seal in boiling water first to soften them but they cool quickly. I found I dont need to bother. Just man-handle them into position. Approach the top seal from the top- going over the piston rod. The other two can go over the bottom edge.

            Once all three are in place twist them around a few times in their grooves. This will help to spread the lubricant around on the inside edges coating everything.





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            • #7
              Re: How to Change Seals: The Ponte Vecchio Lusso Way!

              Time to put it back together. Start by placing the alloy guide over the piston and seals. Do this going over the top- down the piston rod. The ring has a rounded edge on one side to guide over the seals. Push it on until it is flush with the base of the piston.

              Put the spring back in place and insert the piston and spring into the group. Take care that the hole in the piston shaft is aligned as it was at the start. Lock the PF tool in place and wind the hand screw up until the piston shaft sticks up a few mm higher than the top of the group- the same position as when you removed the pin at the start:





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              • #8
                Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                You can adjust the position of the hole in the piston rod with a screwdriver until it is straight. Now you can replace the pin, and the C clip.

                You can also put a few drops of Olive Oil onto the piston rod at the top here. It will run down the piston and stop any squeeks. Just a drop or two on the edges where the piston rod enters the group. It will find its own way down.

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                • #9
                  Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                  Thats It- almost done. The seals are changed and the piston is locked into position again. You can now remove the PF Tool- place the little screen replacement disk into the handle with the screen sitting on top. Lock it onto the machine again and tighten the hand screw a little. You will hear a click when the filterscreen has clicked back into position.

                  You Done! 8-)

                  First group took me 20 minutes- I think I had the second one done in 12 :-?

                  One last thing: Testing

                  Grind up some fresh beans and test each group...


                  Perfecto!

                  I am in love with this little tool!







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                  • #10
                    Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                    If you are reading this but have no access to the special tool the entire process can be done in pretty much the same manner using a G clamp. You use the clamp to raise and lower the piston just as the special tool is used here. However it is more tricky and you must use your hands to keep the clamp in position and guide it throughout the process. It will want to slip- and if it does the spring can jump out. There is not too much pressure though- nothing explosive.  Just go slow and keep adjusting the position of the clamp as you go. On the top of the piston there is only a little room for the clamp to cling to. You also need to leave some clearance so that you can remove the locking pin when the time comes. You will need to remove the drip tray so that the clamp handle can run through that space. Place the machine on a bench with the front edge overhanging.

                    Also when you re-insert the piston you wont have the sleeve to hold the seals in tight. Therefore you will need to take care and screw the piston in slowly: stopping when the edge of the middle seal hits the piston walls. At this point you will need to use a small suitable tool to push the leading edge of the seal into the piston chamber- working all the way around- before you screw the piston all the way up. If you dont do this the edge of the second seal will likely catch on the piston wall and tear.

                    It is completely do-able though. Before this tool came along I did it this way. The first time it is hateful the second-merely an annoyance...

                    You also need to put the filter plate back in place by hand: use a tamper or similar object to tap/push it back into place evenly.

                    here is how the G clamp set-up looks:





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                    • #11
                      Re: How to Change Seals: The Ponte Vecchio Lusso Way!


                      Brilliant guide Jack! I cant wait to have a go with the PV tool - what a clever way to make the whole process so much simpler.

                      Sniff

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                      • #12
                        Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                        What a terrific post Jack- to demystify a tricky job and turn it into something many owners will look forward to once they borrow your PV tool...

                        This one has gotta be worth a technical tinkerer award for mine. [smiley=thumbsup.gif]

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                        • #13
                          Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                          Nice jack, very nice. Great "how to"

                          Also another little tip is to press the shower screen on by pressing in the centre of the screen. I use my thumbs and hold onto the group pushing up. The first time they can be quite stiff.

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                          • #14
                            Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                            A comprehensive and informative guide Jack, you clearly put a lot of time into documenting the process.

                            That tool does look like something Id knock together in my garage rather than something a manufacturer would sell as a service tool. If I still worked in product support, there is no way Id let a tool like that leave the factory. Fine as a prototype, but not a finished item - they didnt even use a new portafilter.

                            Also, why did it take so long for you to find out the correct way to change seals?
                            Seems to me this is a routine service task for which I would expect the manufacturer to provide all necessary info to their service channels. It makes me wonder what other important service info they have yet to give you.

                            Kudos for making the info available, but a big thumbs down to PV for their service and support.

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                            • #15
                              Re: How to Change Seals: The Ponte Vecchio Lusso Way!

                              Originally posted by 3F3739313329293539315A0 link=1307713119/13#13 date=1307751910
                              That tool does look like something Id knock together in my garage rather than something a manufacturer would sell as a service tool. If I still worked in product support, there is no way Id let a tool like that leave the factory. Fine as a prototype, but not a finished item - they didnt even use a new portafilter.
                                I was thinking same and that my mechanic backyard engineer friend could make much neater/better finished tool... given the PF

                              Jack, well done this makes the PV more acceptable to female - just have to be able to manhandle the new seals into place.

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