Case CRAWLER DOZER 650L TIER3 - Page 41

DISTRIBUTIONSYSTEMS-PRIMARYHYDRAULICPOWERSYSTEM
PRIMARYHYDRAULICPOWERSYSTEM-Cleaning
1.Contaminationinthehydraulicsystemisamajor
causeofthemalfunctionofhydrauliccomponents.
Contaminationisanyforeignmaterialinthehydraulic
oil.Contaminationcanenterthehydraulicsystemin
severalways.
(A)Whenyoudraintheoilordisconnectanyline.
(B)Whenyoudisassembleacomponent.
(C)Fromnormalwearofthehydrauliccomponents.
(D)Fromdamagedorwornseals.
(E)Fromadamagedcomponentinthehydraulicsys-
tem.
2.Allhydraulicsystemsoperatewithsomecontami-
nation.Thedesignofthecomponentsinthishy-
draulicsystempermitsefcientoperationwithasmall
amountofcontamination.Anincreaseinthisamount
ofcontaminationcancauseproblemsinthehydraulic
system.Thefollowinglistincludessomeofthese
problems.
(A)Cylinderrodsealsleak.
(B)Controlvalvespoolsdonotreturntoneutral.
(C)Movementofcontrolvalvespoolsisdifcult.
(D)Hydraulicoilbecomestoohot.
(E)Pumpgears,housing,andotherpartswear
rapidly.
(F)Reliefvalvesorcheckvalvesheldopenbydirt.
(G)Quickfailureofcomponentsthathavebeenre-
paired.
(H)Cycletimesareslow;machinedoesnothave
enoughpower.
3.Ifyourmachinehasanyoftheseproblems,check
thehydraulicoilforcontamination.Seetypesofcon-
taminationbelow.Ifyoundcontamination,usethe
PortableFiltertocleanthehydraulicsystem.
NOTE:Therearetwotypesofcontamination,microscopic
andvisible.
4.Microscopiccontaminationoccurswhenveryne
particlesofforeignmaterialareinsuspensioninthe
hydraulicoil.
5.Theseparticlesaretoosmalltoseeorfeel.Micro-
scopiccontaminationcanbefoundbyidentication
ofthefollowingproblemsorbytestinginalaboratory.
Examplesoftheproblems:
(A)Cylinderrodsealleak.
(B)ControlvalvespoolsdonotreturntoNEUTRAL.
(C)Thehydraulicsystemhasahighoperatingtem-
perature.
8426083121/08/2009
A.10.A/
11