PRIMARY HYDRAULIC PUMP OPERATION
Primary and backup pumps should not be operated at
same time. Hydraulic system damage may result.
The M992 uses either a primary or backup pump to provide
power for operation of the stacker, conveyor and upper
rear door (ballistic shield). The primary pump is driven by
the APU; the backup pump is driven by the vehicle main
engine. The primary pump should be used during normal
operation. The backup pump should be reserved for emer-
gency use. For backup pump operation see page 2-236.
Operating the Primary Pump
Be sure hydraulic reservoir ball valve (1) is OPEN be-
fore turning hydraulic pump on. Hydraulic system
damage will result from operating pump with ball valve
1. Check to see that hydrau-
lic resevoir ball valve (1)