Hi i have problem trying to adjust the brew pressure.
the screw on the rotary pump under the screw adjusted ring clamp is
filled with calcification. i assume this is the way to adjust the brew pressure.
i can open the bolt that the screw is part of but the screw is the device i believe that adjusts the brew pressure.

unless i'm way off and there is another method to adjust the brew pressure.

please respond

A pic of your particular situation would be most helpful BUT, lacking that, shut off the water supply to the machine, remove the part you can, and soak in a small glass of white vinegar for 30-45 minutes. Now try to adjust while it is off the pump.

If successful, reinstall and adjust pressure to 9.0 bar during a short flush - I assume your machine has a pressure gage.