Toro Groundsmaster 7210 - Page 101

Performthetractionreliefvalvepressuretestifyouidentifyatractioncircuit
problem.Thistestdeterminesifatransmissionreliefvalveoperatescorrectly.
TestProcedure
1.Ensurethatthehydraulicuidisatnormaloperatingtemperature.
2.EnsurethatthetractiondriveiscorrectlyadjustedfortheNEUTRALposition.
WARNING
Beforedisconnectingordoinganyworkonthehydraulicsystem,
releaseallthepressureinthesystem;refertoReleasingPressure
fromtheHydraulicSystem(page4–11).
3.Parkthemachineonalevelsurface,lowerthecuttingdeck(orimplement),
shutofftheengine,anddonotsettheparkingbrake.
4.ReadallWarning,Cautions,andprecautionslistedatthebeginningofthis
section.
5.Cleanthetransmissionareaaroundthetractioncircuithosesonthetopofthe
transmission(Figure42).Determinewhichtractionreliefvalveistobetested.
6.Disconnectthehydraulichosefromthetransmissionpumpoutletttingto
testthereliefvalve(Figure42):
ReliefValvetobeTestedPumpOutlet
Rightsideforward
PortA
RightsidereversePortB
LeftsideforwardPortC
Leftsidereverse
PortD
7.Installahydraulictester(pressureandow)inserieswiththepumpoutlet
anddisconnectedhose.Ensurethatthetesterowarrowpointsfromthe
pumpoutletportandtowardthehoseforthereliefvalvedirectionthatistobe
tested.Ensurethattheow-controlvalveonthetesterisfullyopen.
8.Starttheengineandrunitatlow-idlespeed(1,400rpm).Checkfor
hydraulic-uidleaksfromthetestconnectionsandcorrectbeforecontinuing
thetest.
IMPORTANT
Donotruntheengineatfullspeedwhenperformingthistestusing
Torohydraulictester(pressureandow)(TOR214678).Thetraction
pumpoutputatfullenginespeedcandamagethehydraulictester.
9.Useaphototactomeasuretheenginespeed,movethethrottlesothatthe
enginespeedis2,800rpm(notfullspeed).
10.Completelyclosetheowcontrolvalveonthetester.
11.Keepthetraction-controlleverintheNEUTRALpositionforthetransmission
pumpthatisnottested.
12.Carefullymonitorthetesterpressuregauge,haveanoperatorslowlypush
thetractionleverforthepumpbeingtested(rightsideorleftside)inthe
directionbeingtested(forwardorreverse)untilthepressuregaugestabilizes
indicatingthatthereliefvalvehasopened.
Groundsmaster7210
Page4–41
HydraulicSystem:TestingtheHydraulicSystem
16222SLRevC