Post By bb2wa
Replacing Ulka pump
Two part post here
I had a funny issue in my VBM Domobar Super where every once in a while when I pulled the lever the machine wouldn't reach full pressure. Seemed to happen more when the machine had been on for a while. I troubleshooted the problem by replacing the over pressure valve and overhauling the e61 group head but no improvement. On a whim I replaced the ulka ex5 pump, the machine is second hand and I don't know it's age and hadn't noticed anything off but figured that was my last shot before I narrowed it down to electrics which I would have had to of taken it to a service centre to fix. I can't believe the change in the machine! Coffee is vastly improved. What I can't work out if the opv is opening at the same pressure a pump that is perhaps struggling to hit that pressure and a pump that does it easily could make such a difference? I have the OPV set to 9.5bar at the portafilter.
Secondly I contemplated when replacing the pump trying to replace it with a rotary pump and electric motor to make it possible to plumb my machine into mains water. I decided against it for the time being but may try it in the future. Has anyone tried this? Is there an easy way to achieve this?
In practical terms, pressure is pressure when within identical confined volume and OPV setting.
The new pump will just get up there a bit quicker...
The Ulka pump is easy to install and cheap. ($50-). Why bother changing to a rotary? The real noise is in the coffee grinder and the start of steaming.