Chapter5
HydraulicSystem
TableofContents
GeneralInformation..............................................................................................................................5–3
Operator’sManual.............................................................................................................................5–3
RelievingHydraulicSystemPressure................................................................................................5–3
TowingTractionUnit...........................................................................................................................5–3
TractionCircuitComponentFailure....................................................................................................5–5
HydraulicHoses.................................................................................................................................5–6
InstallingHydraulicHosesandTubes(O-RingFaceSeal).................................................................5–7
InstallingtheHydraulicFittings(SAEStraightThreadO-RingFittings)...............................................5–9
HydraulicSchematic............................................................................................................................5–12
HydraulicFlowDiagrams.....................................................................................................................5–13
TractionCircuitOperation................................................................................................................5–14
TractionCircuit:LowRangeTractionSpeed(Mow).........................................................................5–16
TractionCircuit:HighRangeTractionSpeed(Transport).................................................................5–19
RaiseCuttingDeck..........................................................................................................................5–22
LowerCuttingDeck..........................................................................................................................5–25
PTOMowCircuit..............................................................................................................................5–28
PTOMowCircuitCuttingDeckBladeBraking..................................................................................5–31
SteeringCircuit................................................................................................................................5–33
Testing.................................................................................................................................................5–36
BeforePerformingHydraulicT ests...................................................................................................5–36
PrecautionsforHydraulicT esting.....................................................................................................5–36
WhichHydraulicT estsAreNecessary?............................................................................................5–37
TractionCircuitChargePressureTest(UsingPressureGauge).......................................................5–39
TractionCircuitReliefPressureTest(UsingPressureGauge).........................................................5–42
CounterbalancePressureTest(UsingPressureGauge)..................................................................5–45
Piston(Traction)PumpFlowTest(UsingTesterwithPressureGauge&40GPMFlow
Meter)...............................................................................................................................................5–47
CuttingDeckCircuitPressureT est(UsingPressureGauge)............................................................5–50
CuttingDeckCircuitReliefPressureT est(UsingTesterwithPressureGaugeand40GPMFlow
Meter)...............................................................................................................................................5–53
CuttingDeckMotorCaseDrainLeakageT est(UsingT esterwithPressureGauge&40GPMFlow
Meter)...............................................................................................................................................5–56
Lift/LowerCircuitReliefPressureT est(UsingPressureGauge).......................................................5–60
SteeringCircuitReliefPressureT est(UsingPressureGauge).........................................................5–63
SteeringCylinderInternalLeakageT est...........................................................................................5–65
GearPump(PTO,Steering,DeckLift/LowerandTractionChargeCircuits)FlowT est(Using
TesterwithPressureGaugesandFlowMeter).................................................................................5–67
Adjustments........................................................................................................................................5–72
AdjustManifoldReliefValves...........................................................................................................5–72
ServiceandRepairs...........................................................................................................................5–73
GeneralPrecautionsforRemovingandInstallingHydraulicSystemComponents...........................5–73
CheckHydraulicLinesandHoses...................................................................................................5–75
PrimingHydraulicPumps.................................................................................................................5–76
FlushHydraulicSystem...................................................................................................................5–77
ChargeHydraulicSystem................................................................................................................5–79
FilteringClosed−LoopTractionCircuit.............................................................................................5–81
HydraulicReservoir..........................................................................................................................5–83
GearPump.......................................................................................................................................5–86
Groundsmaster
®
5900&5910
Page5–1
HydraulicSystem
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