Case 621G - Page 180

4-OPERATINGINSTRUCTIONS
Loadercontrol
Thejoystickisconnectedtoahydraulicaccumulator
throughapressurereducingvalve.Thepurposeofthe
reducingvalveandaccumulatorcombinationis:
•
toallowtheoperatortolowertheloaderarmsiftheen-
ginestopswiththeloaderarmsraised
OR
•
togivethecontrolsystemhydraulicpressureassis-
tancewhenoperatingthemachineatlowidlespeed.
Totestaccumulatorperformance,carryoutthefollowing
procedure:
1.Starttheengine.
2.Raisetheliftarms.
3.Stoptheengine.
4.TurnthekeytoON.
5.Verifythattheindicatorofthehydraulicfunctionslock-
outbuttonisOFF ,allowingthehydraulicfunctionsto
work.
MovetheliftarmcontroltoLOWER.Theloaderbucket
mustlowertotheground.Ifthebucketdoesnotlower
totheground,seetheservicemanualforthismachineor
contactyourdealer.
Brakeaccumulators
Twohydraulicaccumulatorsareconnectedinthebrake
system.Theaccumulatorsprovidethebrakemodulating
valvewithapositivesupplyofpressurizedhydraulicuid.
Periodicallytesttheaccumulatorsforcorrectoperation.
1.Starttheengine.
2.Runtheengineat1/2throttlefor15s.
3.Stoptheengine.
4.Withoutstartingtheengine,turntheignitionkeytothe
ONposition.Afterthediagnosticcheckcompletion,
conrmthatthebrakepressurelightisOFF .
5.Repeatedlypumpthebrakepedaluntilthebrake
pressurelampilluminates.Whenpumpingthebrake
pedal,thereshouldbesomeresistancepressurefelt.
Youshouldfeelaslightincreaseinthepressureas
youpumpthebrakes.
6.Afterthelampilluminates,continuetopumpthebrake
pedalandcountthenumberoffullapplications.
NOTE:ifyoucancompletesixfullbrakeapplicationsafter
theindicatorlampilluminates,theaccumulatorsarework-
ingcorrectly.Ifyoucannotcompletesixapplications,see
theservicemanualforthismachineorcontactyourdealer.
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