Service Manual

Chapter5
HydraulicSystem
TableofContents
GeneralInformation..............................................................................................................................5–3
Operator’sManual.............................................................................................................................5–3
CheckHydraulicFluid........................................................................................................................5–3
RelievingHydraulicSystemPressure................................................................................................5–3
TowingTractionUnit...........................................................................................................................5–4
TractionCircuitComponentFailure....................................................................................................5–6
HydraulicHoses.................................................................................................................................5–7
InstallingHydraulicHosesandTubes(O-RingFaceSeal).................................................................5–8
InstallingtheHydraulicFittings(SAEStraightThreadO-RingFittings).............................................5–10
HydraulicSchematic............................................................................................................................5–13
HydraulicFlowDiagrams.....................................................................................................................5–14
TractionCircuit:LOWSpeed(Mow)................................................................................................5–15
TractionCircuit:HISpeed(Transport).............................................................................................5–17
LowerCuttingDeck..........................................................................................................................5–20
RaiseCuttingDeck.........................................................................................................................5–23
MowCircuit......................................................................................................................................5–26
MowCircuitCuttingDeckBladeBraking..........................................................................................5–29
SteeringCircuit................................................................................................................................5–30
EngineCoolingFanCircuit..............................................................................................................5–33
Testing.................................................................................................................................................5–36
PrecautionsforHydraulicT esting.....................................................................................................5–36
WhichHydraulicT estsAreNecessary?............................................................................................5–37
TractionCircuitChargePressure(UsingPressureGauge)..............................................................5–38
TractionCircuitReliefPressure(UsingPressureGauge).................................................................5–41
CounterbalancePressure(UsingPressureGauge).........................................................................5–45
ReverseTractionCircuitReducingValve(PR)Pressure(UsingPressureGauge)............................5–48
RearTractionCircuitReliefValve(RV)Pressure(UsingPressureGauge).......................................5–51
Piston(Traction)PumpFlowTest(UsingTesterwithPressureGaugeandFlow
Meter)...............................................................................................................................................5–54
CuttingDeckCircuitPressure(UsingPressureGauge)...................................................................5–57
PTOReliefPressure(UsingT esterwithPressureGaugeandFlowMeter).......................................5–59
CuttingDeckMotorCaseDrainLeakage(UsingTesterwithPressureGaugeandFlow
Meter)...............................................................................................................................................5–62
Lift/LowerCircuitReliefPressure(UsingPressureGauge)..............................................................5–65
SteeringCircuitReliefPressure(UsingPressureGauge)................................................................5–68
SteeringCylinderInternalLeakage..................................................................................................5–71
EngineCoolingFanCircuit(UsingPressureGaugeandPhototac)..................................................5–73
EngineCoolingFanMotorCaseDrainLeakageT est.......................................................................5–76
GearPumpFlow(UsingT esterwithPressureGaugeandFlowMeter).............................................5–79
Adjustments........................................................................................................................................5–82
AdjustControlManifoldReliefValves...............................................................................................5–82
ServiceandRepairs...........................................................................................................................5–83
GeneralPrecautionsforRemovingandInstallingHydraulicSystemComponents...........................5–83
CheckHydraulicLinesandHoses...................................................................................................5–85
PrimingHydraulicPumps.................................................................................................................5–86
FlushHydraulicSystem...................................................................................................................5–87
FilteringClosed−LoopTractionCircuit.............................................................................................5–89
ChargeHydraulicSystem................................................................................................................5–91
Groundsmaster
®
4100-D&4110-D
Page5–1
HydraulicSystem
13203SLRevE