Toro Greensmaster 3120 - Page 95

TractionCircuitTesting–TractionPump(P1)FlowandRelief
PressureTest(continued)
5.Disconnecthosefromtractionpump“A”port;refertoFigure34.
6.Installtesterinserieswiththepumpandthedisconnectedhose.Makesure
thetesterisinstalledinthecorrectowdirectionandthetesterowcontrol
valveisfullyopen.
7.Startengine.Movethrottletofullspeed(2850±50RPM).
8.Makesurehydraulicuidisatnormaloperatingtemperaturebyoperatingthe
machineforapproximately10minutes.
9.Verifyandrecordenginespeedwithaphototach.
CAUTION
Useextremecautionwhenperformingthistest.Thetractionunit
wheelswillberotatingduringthetest.
10.VerifypumpowatNoLoadasfollows:
A.Slowlydepressforwardtractionpedaltofullforwardposition.
B.Unrestrictedpumpoutputshouldbeapproximately54.9LPM(14.5
GPM).Recordtesterpressureandowreadings.
11.VerifypumpowUnderLoadasfollows:
A.Slowlydepressforwardtractionpedaltofullforwardposition.
B.Applyanadditionalloadof6890to10340kPa(1000to1500PSI)by
slowlyclosingtheowmeter.
C.Recordtesterpressureandowreadings.
12.Verifytractionpumpreliefvalveoperationasfollows:
A.Withthetractionpedalintheneutralposition,fullyclosetheowmeter
owcontrolvalve.
B.Slowlydepressthetractionpedaltowardtheforwardposition.
C.Systempressureshouldreachapproximately20340kPa(2950PSI)
beforethereliefvalveopens.Recordtesterpressurereading.
Note:Thereliefvalvesettingis19995kPa(2900PSI).Anadditional345
kPa(50PSI)isnecessarytoovercomesystemchargepressurebefore
thereliefvalveopens.
D.Releasetractionpedal,openowcontrolvalvefully,movethrottletolow
speedandturntheengineOFF.
13.Ifreliefpressurecannotbemetorisgreaterthanspecied,theforward
directiontractionreliefvalveisfaultyandshouldbereplaced.
14.TheUnderLoadtestowreading(step10)shouldnotdropmorethan12%
whencomparedtotheNoLoadtestowreading(step11).Adifference
ofmorethan12%mayindicatethetractionpumpiswornandshouldbe
repairedorreplaced.
15.Removetesterandreconnecthydraulichosetopump“A”port.
16.Checkuidlevelinhydraulictankandadjustasnecessary;refertotraction
unitOperator’sManual.
Greensmaster3120
Page4–49
HydraulicSystem:TestingtheHydraulicSystem
17230SLRevC