MAINTENANCE
7-34
D. Hydraulic System
Inspection and Maintenance of Hydraulic Equipment
d
CAUTION: When checking and/or servicing the
hydraulic components, pay special attention to the
following points.
1. Parkthemachinefollowingthesameproceduresas
describedonpage7-7forpreparationforinspectionand
maintenance.
2. Begin servicing hydraulic components only after
components, hydraulic oil and lubricants are completely
cooled, and after releasing residual pressure.
2.1 Beforecheckingand/orservicingthehydraulicsystem,
be sure to release the residual pressure from the
cylindercircuitsoftheboom,armandthebucket,
swing piping and pilot piping. An accumulator can be
installed on some models of this machine as an option
to be capable of moving the front attachment for
specified time (around 10 seconds) after stopping the
engine.
2.2 Bleedairfromthehydraulicoiltanktoreleaseinternal
pressure.
2.3 Immediatelyafteroperation,allhydrauliccomponents
and hydraulic oil or lubricants are hot and highly
pressurized.Begininspectionand/ormaintenance
workonlyafterthemachinehascooleddown.
Servicingheatedandpressurizedhydraulic
componentsmaycauseplugs,screwsand/oroiltofly
off or escape suddenly, possibly resulting in personal
injury. Hydraulic components may be pressurized even
when cooled.
Keep body parts and face away from the front of plugs
or screws when removing them.
2.4 Evenafterairpressureinthehydraulicoiltankis
released,whenthemachineisparkingonaslope,the
oil pressure in the travel motor and the swing motor
circuits are maintained at high pressure as the reaction
force of the machine weight is constantly applied
tothetravelmotor.Nevercheckand/orservicethe
machineparkingonaslope.