Hello All, Seems I have kicked a hornets nest here. Not my intention to stir things quite so much. The pre-infusion pressure may begin quite low 2-3 bar but very rapidly increases to what the pump is capable of. At least 9 bar but some have reported the pump is factory set at 11 bar in some cases. I was thinking that for versatility and small outlay (in comparison to an additional machine purchase) that the mods would give me what essentially would be a traditional commercial lever and the flexibility to change how pre-infusion affects the puck and hence the extraction results. The gauge would be a real time display of pre-infusion pressure whether being left on one setting throughout the extraction or as an indicator of changing pressure using the dimmer switch during extraction pre-infusion. I am not that concerned with the pressure during the spring phase; as I said, I am interested mainly in pre-infusion at this stage. As the water flow system is essentially an 'open' system from the check valve to the group head, a gauge could be connected in the system before the check valve. As to warranty, given my machine is about 2 years old, it would be out of warranty coverage. Anyway, glad this has gotten people thinking about things and possibilities. I would be still interested if someone knows either an individual or service company in Brisbane that could do the work for me. Again thanks for your time and I respect your opinions on the matter. Kind regards, Pete
