I replaced the plastic piston with a brass version from Espresso Parts North West, and I feel the money spent is justified. The brass piston is considerably heavier than the plastic, adds a more substantial feel to pulling the lever, and seems to offer a bit smoother action due to the increased weight. I've read that brass will retain more coffee residue than plastic, but I'm not too concerned. I've had this machine for a year, and this is the first time I've removed the dispersion screen and piston. Surprisingly, there was no coffee residue in the grouphead, and only a tiny bit on the inside of the screen. It seems not much but air really gets sucked up into the grouphead if you do a second pull. I've also read in comparisons that the Elektra Microcasa and Olympia Cremina produce shots just a bit better than the Pavoni. I've only pulled a few shots with this new piston so far, but the results show a bit more improvement. Perhaps this piston evens out the playing field now between all these machines. I suppose in the end, it's somewhat akin to adding better breathing muffler tips and air filters to a car. Just a bit more horsepower, but noticeable to the driver.
I broke the sight glass trying to fit the new piston. I turned the machine over, not realising the pressure gauge was also receiving pressure while pushing in the piston. I heard a faint "crack" sound, and when I went to test the machine at pressure, there was a leak from the top of the sight glass area. At first I thought it was the gauge which was compromised, but when I took that area apart, here's what I found.
Luckily, only the top few cm of the glass broke off (I found all the bits and thoroughly rinsed the machine for scattered shards), and it was still long enough to be covered by the gaskets. Here's the repositioned sight glass, machine up to pressure, and no leaks!
Of course I'm not going to rely on this holding forever, so I've ordered a new sight glass, only $6 from Espresso Parts.
And lastly, I changed out the steam tip. Finally my first Krups steam toy has a use. I noticed this steam tip happens to fit the Gaggia's wand, with a bit of teflon pipe thread tape to stop any leaks.
I drilled out the hole to enlarge it a bit, and now it steams quicker than the original, and results in effortless microfoam consistently. I don't drink enough milk drinks to get in enough practise with the three holed tip, and this tip eliminates the need for further practise.
I think I've now brought this machine up to its best possible performance, and I'd love to have a go at a side by side comparison with an Elektra Microcasa or Olympia Cremina, unfortunately, I don't know anybody with either.
Hogfire
