Toro Groundsmaster 5910 Series - Page 115

TractionCircuitOperation(continued)
Thenalgearpumpsectionsuppliesoiltothesteering,cuttingdeckliftand
tractionchargecircuits.Thisgearpumpsectionprovidesaconstantsupplyof
chargeoiltothetractioncircuittomakeupforoilthatislosttointernalleakage
inthetractionpumpandwheelmotors.Chargepumpowisdirectedthrough
thechargeoillterattachedtothesteering/deckliftmanifoldbeforeenteringthe
pistonpump.Abypassvalveislocatedinthemanifoldtoallowchargeoilowto
theclosedtractionloopifthelterbecomesplugged.
Tractionchargepressureislimitedto20bar(290PSI)byareliefvalvelocatedin
thepistonpump.Chargepressuregoingintothepumpcanbemeasuredatthe
pressuretestport(CH1)locatedonthesteering/deckliftmanifold.Measured
pressureshouldbeapproximately26bar(380psi)with150Foil.Charge
pressureinsidethepumpcanbemeasuredatthepressureport(AM3)located
ontheLHside.
Thetractionmanifoldincludesashuttlevalve(SH)forcoolingoftheclosed
looptractioncircuit.Theshuttlevalvespoolisshiftedbytractionpressureand
allowshydraulicuidtobleedoffforcoolingoftheclosedlooptractioncircuit.
Thechargesystemreplenishesoilthatisbledfromthetractioncircuitdueto
shuttlevalveoperation.
Thefrontwheelmotorsincludeaninternal,multi−discparkingbrakesystem.The
parkingbrakeisautomaticallyappliedbyinternalmotorspringpressurewhen
theengineisnotrunningorchargepressuredropsbelow12bar(174psi).The
brakeisreleasedwhentheengineisrunning,chargepressureisabove12bar
(174psi)andtheparkingbrakerockerswitchisinthedisengagedposition.
Groundsmaster
®
5900&5910
Page5–15
HydraulicSystem:HydraulicFlowDiagrams
16227SLRevB