Service Manual

TestProcedure(continued)
9.Usethehydraulichosekittoconnecttestertothemachine;refertoHydraulic
HoseKit(page5–40).Ensurethatthettingandhoseconnectionsare
properlytightened.Also,ensurethattheowcontrolvalveontesterisfully
open.
CAUTION
Duringthisprocedure,allthewheelswillbeoffthegroundand
rotating.Ensurethatthemachineiswellsupportedsoitwillnot
moveandaccidentallyfalltopreventinjuringanyonearoundthe
machine.
10.Starttheengineandrunitatlow-idlespeed.Checkforhydraulic-uidleaks
fromthetestconnectionsandcorrectbeforecontinuingthetest.
11.Withtheenginerunning,movethethrottletofullspeed(3,100to3,250rpm)
position.Useatachometertocheckthattheenginespeediscorrect.
12.VerifythepumpowatNoLoadasfollows:
A.Slowlypressthetractionpedaltofullyforwardposition.
B.Recordthetesterpressureandowreadingsatnoload.Unrestricted
pumpoutputshouldbeapproximately62L/minute(16.3gallons/minute)
at8,963kPa(1,300psi).
13.VerifythepumpowUnderLoadasfollows:
A.Slowlypressthetractionpedaltofullyforwardposition,andkeepthe
pedalpressedintheforwardposition.
B.Applyanadditionalloadof8,963to13,100kPa(1,300to1,900psi)by
slowlyclosingtheowmeter.Theowmeterpressuregaugeshould
read16,545to20,000kPa(2,400to2,900psi).
C.Recordthetesterpressureandowreadingsunderload.
14.Verifythetractionreliefvalveoperationasfollows:
A.ReturnthetractionpedaltotheNEUTRALposition.
B.Fullyclosetheowmeterowcontrolvalve.
C.Slowlysetthetractionpedaltofullforwardposition.
D.Recordthetesterpressurereading.
Thesystempressureshouldreach32,400to33,100kPa(4,700to4,800
psi)beforethereliefvalveopens.
Note:Thereliefvalvesettingis32,500kPa(4,713psi).Anadditional
690to1,030kPa(100to200psi)isnecessarytoovercomesystem
chargepressurebeforethereliefvalveopens.
E.Releasethetractionpedal,opentheowcontrolvalvefully,movethe
throttletolowspeed,andshutofftheengine.
15.Ifthereliefpressurecannotbemetorisgreaterthanspecied,thetraction
reliefvalveisdamagedandshouldbereplaced.
16.Theunderloadtestowreading(step13C)shouldnotdropmorethan12%
whencomparedtothenoloadtestowreading(step12B).Adifference
ofmorethan12%mayindicatethehydraulicpumpiswornandshouldbe
repairedorreplaced.
17.Afteryoucompletethetesting,disconnectthetesterandconnectthehoseto
thepumptting.
HydraulicSystem:TestingtheHydraulicSystem
Page5–64
Groundsmaster
®
3280-D/3320
05138SLRevB