Case CX490C - Hydraulic contamination

INTRODUCTION
Hydrauliccontamination
Contaminationinthehydraulicsystemisamajorcauseofthemalfunctionofhydrauliccomponents.Contamination
isanyforeignmaterialinthehydraulicoil.
Contaminationcanenterthehydraulicsysteminseveralways:
•
Whenyoudraintheoilordisconnectanyline
•
Whenyoudisassembleacomponent
•
Fromnormalwearofthehydrauliccomponents
•
Fromdamagedsealsorwornseals
•
Fromadamagedcomponentinthehydraulicsystem
Allhydraulicsystemsoperatewithsomecontamination.Thedesignofthecomponentsinthishydraulicsystemper-
mitsefcientoperationwithasmallamountofcontamination.Anincreaseinthisamountofcontaminationcancause
problemsinthehydraulicsystem.
Thefollowinglistincludessomeoftheseproblems:
•
Cylinderrodsealsthatleak
•
Controlvalvespoolsthatdonotreturntoneutral
•
Movementofcontrolvalvespoolsisdifcult
•
Hydraulicoilthatbecomestoohot
•
Pumpgears,housing,andotherpartsthatwearrapidly
•
Reliefvalvesorcheckvalvesheldopenbydirt
•
Quickfailureofcomponentsthathavebeenrepaired
•
Slowcycletimesareslow.Themachinedoesnothaveenoughpower.
Ifyourmachinehasanyoftheseproblems,checkthehydraulicoilforcontamination.
Therearetwotypesofcontamination:microscopicandvisible.
Microscopiccontaminationoccurswhenveryneparticlesofforeignmaterialaresuspendedinthehydraulicoil.
Theseparticlesaretoosmalltoseeorfeel.Microscopiccontaminationcanbefoundbyidenticationofthefollowing
problemsorbytestinginalaboratory.
Examplesofproblemscausedbymicroscopiccontamination:
•
Cylinderrodsealsthatleak
•
Controlvalvespoolsthatdonotreturntoneutral
•
Thehydraulicsystemhasahighoperatingtemperature
Visiblecontaminationisforeignmaterialthatcanbefoundbysight,touch,orodor.Visiblecontaminationcancause
asuddenfailureofcomponents.
Examplesofproblemscausedbyvisiblecontamination:
•
Particlesofmetalordirtintheoil
•
Airintheoil
•
Darkorthickoil
•
Oilwithanodorofburnedoil
•
Waterintheoil
Ifyoundcontamination,useaportableltertocleanthehydraulicsystem.
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