I am in the process of fixing up a rancilio s27 that I purchased on craigslist a few years ago. I waited to fix it up until I moved into my new house and had room to work in my basement! The time finally arrived and I have enjoyed the rebuild process so far, but don't know how to fix some lingering problems. This is my first espresso machine rebuild, and first espresso machine period, so I don't know what I am doing for the most part. Browsing this site has been very helpful in figuring out the initial steps!
I disassembled and descaled the boiler, group head, and pipes in citric acid. I purchased new gaskets for the heat exchanger, boiler, and group head and rebuilt the steam wand and water dispenser. After reassembling everything, the boiler fills, it heats up, and the water dispenser and steam wand seem to work well. The machine is hooked up to a flojet pumping from a 5 gallon water jug.
When trying to brew espresso, I get a ton of steam from the group head with very little water - a few drops at most. If the machine is cold and I hit the button to brew, i get no water from the group head at all, although I do hear the pump kick on. I am not sure if this is normal behavior. The pressure gauge to the boiler is not working, so I'm not sure what the pressure in the tank is. I hoped that the descale would fix that problem, but it did not. Last night, the gauge moved up, but then crashed back down to zero after some time, no idea why. Not sure if I caused this by overtightening the t-fitting on top of the boiler which cause me to have to bend the pipe to the pressure gauge to get things to fit. In addition, once the machine is hot, I continue to hear a ton of hissing from the anti-syphon valve, which from what I understand, should seal once the machine is up to temperature?
Not sure how I should attack this problem! My novice guess is possibly a pstat problem?