I wouldn't directly attribute the behavior of the HEPI Pumps to open chambers.  Indirectly though, the open chambers are giving us an opportunity to work on the tables but that work will necessarily or at least likely disrupt the HEPI control loops causing them to trip (same reason we typically lock the ISI) causing the positions to change and additionally limiting work (not allowing people walk on the HEPI structure.)  So we have locked the HEPI structures (as close as I could to past controlled positions) and in so doing provided an opportunity to do some very invasive maintenance--change the 'oil' filters.  Invasive as the system is down for weeks as we recirculate the fluid to bleed introduced air out of the system and capture any possible foreign debris that was inadvertently introduced.  The PUMP signatures being 'all over' is this regimen of slowly circulating the fluid to clean the system after the filter change.  This will continue for a few more weeks.