Case 521G - Hydraulic System 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
•
Slowcycletimesoralackofpower.
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.
48082189_EN14/02/2017
21