Chromatography Forum

I came across an odd error on one of my systems in the last few days. My pump shut off twice mid-analysis, and my Chemstation sequence log said something to the effect of "Pump Drive Valve (pump B) error". Apparently there was 'something' that was causing the pump to have to work too hard to do its job (and thus need more current to operate) in the pre-pressure-sensor part of my binary Agilent G1312A pump, and the pump drive eventually hit a current limit and shut down the system. The Agilent website said the causes could be a sticking outlet ball valve (amongst other things), so I pulled both outlet ball valves from my system (becaue that took the least effort) and sonicated them at 40 C in dichloromethane/acetone for 30 minutes, then reinstalled them. I also tried to bleed each line after the sonication, to try and purge any 'substance' that might have meandered into my pump by following the flow path in each side of the pump and breaking and then closing each capillary fitting.

Has anyone seen this before? I wasn't seeing anything chromatographically or system-symptomatically that would tell me I had an issue, except for the fact that the system shut down twice in three days. Granted, this problem seemed to be post reservoir/pre pressure sensor, so it's kind of in the hinterlands of pump diagnostics, but if anyone has an idea as to how I can nip it in the bud in the future (without having to perform pump diagnostics on a Sunday at midnight), I would appreciate it.