mitchell,
I don't see a yellow part. Can you help me find the pressurestat and group pressure adjust from the attached picture? My unit appears to be a bit different.

Thanks!

http://www.partsguru.com/images/Img378.png.. see "pressure switch"

it's toward the bottom right of the second photo.. that is the steam pressurestat.

as far as group pressure.. i am not sure, but i think adjusting the rotary pump is easier than adjusting the opv.. or more effective..

you need a pressure gauge to really see what you're working with.. for a machine that has a rotary pump you don't need a liquid filled gauge usually.. just a simple one from a hardware store.. bring your portafilter to ace and have fun explaining to those guys what the hell you're trying to do

Cool... Thanks!

I adjusted the pressurestat and have seen some change. I have noticed the needle on the gauge bounce around a bit during pulling of a shot. Is this typical? Also, it's got a wide band of .8 - 1.2 now.

Yeah, someone else mentioned on CG that adjusting the rotary pump should be easy to do, and better than any OPV adjustments. I'll build a gauge tomorrow.

And I'm sure the guys at ace are going to say, "what that boy need a gauge fer coffee fer?"

Kinda like going to the health food store for citric acid..."you're not going to use it for canning fruit?"

I've highlighted the rotary pump adjustment screw for brew pressure... don't mess with the OPV, it serves as an expansion valve and a safety on a rotary pump machine.

jesawdy,
Thanks for the highlight. It indeed works and I've gotten it from the low ~7 bar pressure up to ~9 now. I built a portafilter gauge and was surprised at the low bar. No wonder the grind on my macap that I use for my andreja nearly choked the s27. Adjusted and tried again and worked much better.

What model do you have? and...
What are your boiler pressure and brew pressure settings? Mine are now .8 - 1.1 and 9.

Thanks!

I am counting on it. I just paid $500.00 for a 1996 S27 last week. This unit is in immaculate condition. The green sides are almost perfect. My S27 saw light coffee house activity. It was service regularly and was last serviced about a year ago. Do you still feel confident you got a good deal? I feel that even though mine is a 1996 model, I got a good deal as well. Do others feel as I do? So far it works flawlessly.

DaSpresso,
Yes, I feel it was a good deal. I have completely disassembled the unit and boiler, cleaned, and rebuilt it making sure everything was working properly. It's a great unit and the rotary pump is awesome. I am trying to convince the wife to let me put it inside the house....still working on it!

I noticed you have a buon cafe 330. I had one from 1994 to about to about a month ago when I gave it away to my in-laws. I wasn't using it for the last 2 years when I went through about 4 Breville 800esxl. When I bought my Andreja Premium in February I go rid of the Breville. The Andreja was a huge improvement, but the S27 rotary pump is awesome.

Build a pressure gauge for your portafilter and check your pressure bar. Read the above and you may need to adjust your boiler pressure and pump pressure.

Enjoy
Darren