What was found
AFTER OPERATING FOR 500 HOURS, THE HYDRAULIC POWER PACK BEGAN TO CAVITATE EITHER BECAUSE OF AIR OR CONTAMINATION. THE SM INSTRUCTIONS CLEARLY STATE 'OPERATE PUMP TO PURGE AIR FROM SYSTEM' WHENEVER REPLACING THE PUMP, A CYLINDER, OR A LINE. UNFORTUNATELY, THESE STEPS WILL NOT PURGE AIR NOR CONTAMINATION FROM THE ACTUATING CYLINDERS.