Service Manual

Table Of Contents
2
3
1
4
g275073
Figure89
1.Frontpumpsection(LHandRHPTO)
2.2
nd
pumpsection(frontPTO)
3.3
rd
pumpsection(coolingfan,lift/lowerandcharge)
4.4
th
pumpsection(steering,chargeandcoolingfan)
Thegearpumpowtestshouldbeperformedtomakesurethatthemow,
steering,lift/lower,coolingfanandtractionchargecircuitshaveadequate
hydraulicow.Thefrontgearpumpsectionprovideshydraulicowfortheside
cuttingdecks(Figure89).Thesecondgearpumpsectionprovideshydraulicow
forthecentercuttingdeck.Thethirdgearpumpsectionprovideshydraulicow
forthecoolingfan,lift/lowerandtractionchargecircuits.Thefourthgearpump
sectionprovideshydraulicowforthesteering,tractionchargeandcoolingfan
circuits.
Note:Overaperiodoftime,thegearsandwearplatesinthegearpumpcan
wear.Awornpumpwillbypassoilandmakethepumplessefcient.Eventually,
enoughoillosswilloccurtocausecircuitproblems(e.g.cuttingdeckmotors
stallingunderheavycuttingconditions,liftorsteeringproblems).Continued
operationwithaworn,inefcientgearpumpcangenerateexcessiveheatand
causedamagetothesealsandothercomponentsinthehydraulicsystem.
ProcedureforGearPumpFlowTest
CAUTION
Preventpersonalinjuryand/ordamagetoequipment.Readall
WARNINGS,CAUTIONSandPrecautionsforHydraulicTestingatthe
beginningofthissection.
1.Parkmachineonalevelsurfacewiththecuttingdecksloweredandoff.
Makesurehydraulicoilisatnormaloperatingtemperature,engineisoffand
theparkingbrakeisapplied.
2.Raiseandsupportoperatorseattogainaccesstogearpump.
3.Determinewhichgearpumpsectionistobetested.Disconnecthydraulic
hosefromttingingearpumpsectionthatistobetested(Figure89).
4.Installtester(owandpressure)inserieswiththedisconnectedhoseand
hydraulicttingingearpumpsection.
5.Makesuretheowcontrolvalveontesterisfullyopen.
HydraulicSystem:Testing
Page5–80
Groundsmaster
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4100-D&4110-D
13203SLRevG