I have blogged in the past about my great experience with the Ponte Vecchio, a lever espresso machine that I have for almost two years. Before owning the Ponte Vicchio, I was using the Pavoni Euripicolla as my main espresso machine. The Ponte Vecchio Lusso really open my eyes to the world of spring lever. First of all, it is very convinience, you are able to steam milk while pulling your shots just like what you are able to do with more expensive heat-exchanger and double boiler; this is a great plus for me since I always have company over and they enjoy cappuccino. Second strong point of the Ponte Vecchio Lusso is it's thermosyphon design; this mean that stable and repeatable brewing temperature is possible much like that of double boilers and heat-exchanger, with the caveat that you must do heating flushes. What I love about my ponte Vecchio Lusso (2 groups version) is that it is capable of making great espresso at commercial pace (I can essentially outpace the speed of my grinders).
With that said, I have not been enjoy espresso from my PV Lusso for the past week or so. I have noticed some drastic changes in the espresso shots that it produce; for instance, creama are much less and not as persistent, and taste is much less refine refined and robust. Sometime I would get sour shot and some time over-extraction leading to bitter taste. I also feel that the brewing pressure is less than it used to be. I would be able to rule out cleanliness issue because I clean the group head of all my espresso machine very obsessively. Also, I feed my machine very clean tasty filtered water. A really critical observation that I noticed with the PV is leaks out of the "vent hole" of the group head.
In the picture above, you can notice the hole right behind the group head. Before, I did not notice any leak and was not even aware of the existance of this hole. About a month ago, I notice every time when I push the lever down to introduce water into the group head, there would we water dripping from the behind of the groups, this is when I became aware of its existence. My theory about the leak and the hole is that when the rubber seals in the group head are worn, the water will be able to leak through the seal and out of the group through this tiny hole. Essentially, the hole are to allow the owner know when it it time to change the seals inside. My other lever machine the Pavoni profesional manual machine do not have this hole.
So my plan for the next two weeks or so it to do some refurb work on my Ponte Vecchio, changing any wearable parts such as seals, the essential being the group piston seals that are leaking. I will be documenting this whole process in the hope that it might be able to help other lever machines owners when it comes to changing the seals on their machines.