The pressure adjusting screw on my pump looks a little different from the one in the diagram from the other thread. It looks like mine is designed to be adjusted without removing the acorn nut. My pump is this one from 1st-line. The label on it has a manufacturer's model number, 132A060F11CB130.

I'll put it back together and try adjusting the pressure with a blind portafilter mounted.

I think I've got it adjusted now, at least for a starting point. It was leaking from the adjustment screw on the acorn nut when I put it back together. Turning the screw a couple of turns clockwise stopped the leak. Then I put the blind portafilter on and got a reading of just over 11 bar, so I backed out the adjustment screw on the pump about 3/4 turn counter-clockwise until I got a reading on my gauge of just over 10 bar. According to the manual that came with my machine, the built-in pressure gauge reads about 1 bar higher than the actual pressure on the coffee grounds in the filter basket, so I should be close to 9 bar actual.

Next I adjusted the OPV valve (turned the adjustment screw clockwise) until the water stopped flowing back into the drip tray. Then I turned it another quarter turn just for good measure.

The group head is now coming back up to temp. I'll draw a shot later when I'm ready for an espresso and adjust by taste from there.

I've got the brew pressure and my grind near where I want it after pulling 5 doubles this afternoon. I'm seeing 10.4 bar on the gauge at full pressure during a pull, so I'm going to try backing off the pressure just a little bit more in the morning.

Dan, thanks for pointing out the pump pressure adjustment. I never realized the pump's pressure and flow could be adjusted. The manual that came with the Vibiemme doesn't mention that. It says to adjust the OPV valve to change the brew pressure.

There is excellent information on the Vibiemme Domobar Super Hx here:
http://www.espressomyespresso.com/

A manual written for your machine is here: http://www.espressocare.com/PDF-Files/V ... Manual.pdf

An electrical diagram for your machine is here: http://users.rcn.com/erics/Illustrations/vibe_ELEC.jpg

Thank you Eric. I used the detailed group head rebuild article on the espressomyespresso site when I rebuilt my group head yesterday. It was a huge help.

That manual you linked to is more detailed overall, and has a more concise and easier to follow descale procedure than the one that came with my machine. It's definitely an improvement. I notice that it also doesn't include information about adjusting the pressure on the Procon pump. That would be a nice addition for owners of rotary pump machines.

The wiring diagram will be handy if I have to rewire anything. I sure hope I won't have to any time soon, though.

I saved copies of everything. Thanks!

The Vibiemme Domobar manual was written by Randy Glass . . . whose site you referenced on the grouphead rebuild adventure.

The electrical diagram was intended for troubleshooting purposes . . . not necessarily rewiring.

I would contact Procon as regards some new O-rings/gaskets for the pressure adjuster on your pump. Parts are very inexpensive whereas shipping, unfortunately, is not.