Toro Groundsmaster 5900 Series - Page 141

ProcedureforTractionCircuitChargePressureTest(continued)
9.Ifthereisnopressure,orpressureislow,checkthefollowingitems:
A.Restrictioningearpumpintakelineorreservoirstrainer.
B.Inspectchargepressurereliefvalvelocatedinthepistonpumpand
adjustifnecessary(seeSauer−DanfossH1ClosedCircuitAxialPiston
PumpsServiceManual).Keepinmindthatoperatingthemachinewith
anelevatedchargepressurecanreduceswash−plateresponsetime.
C.Considerthataforwardorreversereliefvalveinthepistonpumpis
leakingordamaged.
D.Leakageinthesteering/deckliftmanifoldwillaffectchargecircuit
pressure.Considerthatdamagedcartridgesealsinthismanifoldwill
causelowchargecircuitpressureinadditiontoaffectingnormaloperation
ofsteeringand/ordecklift/lowercircuits.
E.Ifnecessary,checkforinternaldamageorwornpartsinthenalgear
pumpsectionwhichsuppliesthechargecircuitwithhydraulicow.A
wornordamagednalgearpumpsectionwillalsoaffectcuttingdeck
lift/lowerandsteeringoperation.
10.Next,withthepressuregaugestillconnectedtothechargepressuretestport,
takeagaugereadingwhileoperatingthemachineinforwardandreverse.
Starttheengine,releaseparkingbrakeandrunengineathighidlespeed
(2530RPM).Pushthetractionpedalforwardwhilemonitoringthepressure
gauge.Repeatforreversedirection.Stopengineandrecordtestresults.
11.Ifchargepressuremeetsspecicationsundernoloadconditions(step6
above),butconsistentlydropsmorethan15%whenundertractionload
(step9above),thepiston(traction)pumpand/orwheelmotor(s)shouldbe
suspectedofwearandinefciency.Whenthepumpand/orwheelmotor(s)
arewornordamaged,thechargecircuitisnotabletokeepupwithinternal
leakageintractioncircuitcomponents.
12.Whenchargepressuretestingiscomplete,disconnectpressuregaugefrom
manifoldtesttting.Lowerandsecurehood.
Groundsmaster
®
5900&5910
Page5–41
HydraulicSystem:Testing
16227SLRevB