Toro Groundsmaster 3320-D - Steering Circuit (Machine Serial Number above 316000000)

SteeringCircuit(MachineSerialNumberabove316000000)
Thechargepumpsuppliesowforthesteeringcircuitandfortheliftcircuit.The
pumpoutputowstothesteeringcontrolvalvebeforereachingtheliftmanifold
sothatthesteeringcircuithaspriority.Thesteeringcircuitpressureislimitedto
7,239kPa(1,050psi)byareliefvalvelocatedinthesteeringcontrolvalve.
Whenthesteeringwheelisnotbeingturnedandtheengineisrunning(hydraulic
pumpinputshaftbeingrotated),chargepumpowentersthesteeringcontrol
valveatthePportandby-passestherotarymeterandsteeringcylinder.Flow
leavesthesteeringcontrolvalvethroughtheEportandisdirectedtothelift
manifold.
LeftTurn
Whenaleftturnismadewiththeenginerunning,theturningofthesteering
wheelpositionsthesteeringcontrolspoolvalvesothattheowgoesthrough
thebottomofthespool.FlowenteringthesteeringcontrolvalveatthePport
passesthroughtherotarymeterandisdirectedouttheLport.Pressureretracts
thesteeringcylinderforaleftturn.Therotarymeterensuresthattheuidowto
thecylinderisproportionaltoamountofsteeringwheelrotation.Theuidleaving
thesteeringcylinderowsbackthroughthespoolvalve,thenouttheTportand
returnstothehydraulicreservoir(frontaxle).
RightTurn
Whenarightturnismadewiththeenginerunning,theturningofthesteering
wheelpositionsthesteeringcontrolspoolvalvesothattheowgoesthroughthe
topofthespool.FlowenteringthesteeringcontrolvalveatthePportpasses
throughtherotarymeterandisdirectedoutportR.Pressureextendsthe
steeringcylinderforarightturn.Therotarymeterensuresthattheuidowto
thecylinderisproportionaltotheamountofsteeringwheelrotation.Theuid
leavingthesteeringcylinderowsbackthroughthespoolvalve,thenouttheT
portandreturntotheoilcoolerandthehydraulicreservoir(frontaxle).
Groundsmaster
®
3280-D/3320
Page5–37
HydraulicSystem:HydraulicFlowDiagrams
05138SLRevB