Toro Groundsmaster 7210 - Page 95

Performthechargereliefvalvepressuretestifyouidentifyatractioncircuit
problem.Thistestdeterminesifthetransmissionchargereliefvalveoperates
correctly.
TestProcedure
1.Ensurethatthehydraulicuidisatnormaloperatingtemperature.
2.EnsurethatthetractiondriveiscorrectlyadjustedfortheNEUTRALposition.
WARNING
Beforedisconnectingordoinganyworkonthehydraulicsystem,
releaseallthepressureinthesystem;refertoReleasingPressure
fromtheHydraulicSystem(page4–11).
3.Parkthemachineonalevelsurface,lowerthecuttingdeck(orimplement),
shutofftheengine,andsettheparkingbrake.
4.ReadallWarning,Cautions,andprecautionslistedatthebeginningofthis
section.
5.Cleanthetransmissionareaaroundthecharge-pressuretestportonthe
rightsideofthetransmission.
6.Removetheplugfromthecharge-pressuretestport.
7.Connecta6,900kPa(1000psi)hydraulic-pressuregaugewithanattached
hydraulichosetothetransmissioncharge-pressureport.
8.EnsurethatthetractionleversareintheNEUTRALLOCKpositionandthe
parkingbrakeisapplied.
9.Starttheengineandrunitatlow-idlespeed(1,400rpm).Checkfor
hydraulic-uidleaksfromthetestconnectionsandcorrectbeforecontinuing
thetest.
10.Operatetheenginebymovingthethrottletofullspeed(3,000rpm).The
pressuregaugereadingshouldreadfrom480to690kPa(70to100psi).
Recordthetestresult.
11.Ifthechargereliefpressurespecicationisnotmet,considerthefollowing:
A.Thetransmissionchargereliefvalveisdamaged.Repairorreplacethe
charge-reliefvalve;refertoServicingtheTransmission(page4–75).
B.Atransmissiontractionreliefvalveorushingvalveisleakingor
damaged;refertoServicingtheTransmission(page4–75).
C.Thechargepumpinthetransmissionisdamaged(thePTOoperation
mayalsobeaffected);refertoServicingtheTransmission(page4–75).
12.Performadynamiccharge-pressuretestbydoingthefollowing:
A.Withthehydraulic-pressuregaugestillconnected,sitintheoperatorseat
andmovethetractionleversforward.
B.Whilethemachineismoving,monitorthechargepressurereadingon
thepressuregauge.
C.Thechargepressureshouldnotdropmorethan15%fromtheinitialtest
reading(Step10)asthemachineismoving(e.g.,iftheinitialcharge
pressureis690kPa(100psi),chargepressurewhilethemachineis
movingshouldbeabove590kPa(85psi).
Groundsmaster7210
Page4–35
HydraulicSystem:TestingtheHydraulicSystem
16222SLRevC