Case CX225SR - Operator Precautions

INTRODUCTION
Hydrauliccontamination(-A.92.A.60)
CX225SR
CLEANINGTHEHYDRAULICSYSTEM
General
Contaminationofthehydraulicsystemisamajorcauseofincorrectoperationofhydrauliccomponents.
Contaminationisindicatedbythepresenceofforeignparticlesinthehydraulicuid.
Contaminationofthehydraulicsystemcanoccurinanyofthefollowingsituations:
1.Whendrainingtheuidordisconnectingahydraulicline.
2.Whendisassemblingacomponent.
3.Duetonormalcomponentwear.
4.Duetodamagedorwornseals.
5.Duetoadamagedcomponentinthehydraulicsystem.
Allhydraulicsystemscanfunctioneveniftheyareslightlycontaminated.Thecomponentsofthehydraulicsystem
aredesignedtosupportslightcontamination.Anyincreaseinthedegreeofcontaminationcancauseserious
problemsinthehydraulicsystem.
Thefollowingisanincompletelistoftheseproblems:
1.Thecylinderrodsealsleak.
2.Controlvalvespoolsdonotreturntotheneutralposition.
3.Controlvalvespoolsdonotmoveeasily.
4.Hydraulicuidistoohot.
5.Hydrauliccomponentswearquickly.
6.Safetyvalvesorcheckvalvesdonotcloseduetocontamination.
7.Repairedcomponentsbreakdownsoon.
8.Cyclesareslow;themachinedoesnothaveenoughpower.
Ifanyoftheabovesituationsoccurs,itisanindicationofexcessivecontaminationofthehydraulicsystem.
Toeliminatecontamination,effectively,refertoPRIMARYHYDRAULICPOWERSYSTEM-Decontaminating
(A.10.A-F .30.A.60).
Typesofcontamination
Contaminationexistsbasicallyintwoforms:microscopicorvisible.
Wespeakofmicroscopiccontaminationwhenverysmallparticlesofforeignbodiesareinsuspensioninthe
hydraulicuid.Theseparticlesaretoosmalltobeseenorfelt.Microscopiccontaminationcanbedetectedby
identifyingtheproblemsrelatingtomicroscopiccontaminationorbylaboratorytests.
Thefollowingareafewexamplesofproblemscausedbymicroscopiccontamination:
•
Thecylinderrodsealsleak.
•
Controlvalvespoolsdonotreturntotheneutralposition.
•
Theoperatingtemperatureofthehydraulicsystemistoohigh.
•
Componentswearquickly.
Wespeakofvisiblecontaminationwhenthepresenceofforeignbodiescanbedetectedvisually,bytouchorby
smell.Visiblecontaminationcancausethesuddenfailureofacomponent.
Thefollowingareafewexamplesofproblemscausedbyvisiblecontamination:
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