Vmac VR70 Manual

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SalesRepServiceInformationSheet
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VMACrotaryscrewcompressorsystemsaredesignedandmachinedtoexactingtolerances.Theyare
uniqueinthattheycontainnoreed‐valvesorothereasilyfouled,fatigue‐pronecomponents.However,
propermaintenanceisneededtoensureperformanceandlongevityofthecompressorsandcanreduce
theneedforprematurerepairorcomponentreplacement.
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Systemfiltersalsoenhanceperformanceandextendcomponentlifebyreducingdamagefromdustand
otherdebris.Foreignparticlesenteringthesystemwilldrasticallydamageorshortenthelifeexpectancy
ofthecompressorandwillresultindamagetobearings,gears,rotorsandtheinsideofthehousing.
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Thefollowingmaintenancescheduleshouldbeobservedtoassuregoodperformanceandlongservice
life.ThehoursindicatedarethosedisplayedontheCompressorControlPanel.Serviceintervalshould
bewhicheveroccurssooner(e.g.,200hoursofoperationor6months)
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UNDERHOODMaintenanceSchedule
50hours:Checkthedrivebelt
200hoursor6months:Replacetheairfilter,oilfilterandchangeoil.Useservicekit#A700019(VR70)
#A700059(VR140)
400hoursor1year:Replacetheairfilter,oilfilter,coalescingelementandchangeoil.Useservicekit
#A700020(VR70)#A700060(VR140)
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PREDATAIRMaintenanceSchedule
PREDATAIR(H600001)
200hoursor6months:Replacetheairfilter,oilfilterandchangeoil
PREDATAIR(H600002andH400001)
500hoursorevery6months
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Inadditiontoregularservicing,besuretocheckthecompressor’sairfilterfrequentlytoensurethatitis
notrestrictedordamaged.Properfiltermaintenanceisalsokeytolongcompressorlife.Regular,
scheduledmaintenanceincludes:
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•inspectingtheaircleanerandmaintainingtheoillevel
•morefrequentserviceinsevereoperatingconditions

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ServiceTips
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•Neverrunthecompressor,drivethevehicleorevenallowthevehicletositparkedwithoutthe
recommendedairfilterandfiltercoverinstalled.
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•AlwaysuseaVMACoilfilterwhichisdesignedtowithstandthehighpressures,notan
automotivefilter.
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•Operatethesystematleastevery30daysfor15minutesatnoloadtoensurebearing
lubricationandrotation.Impactdamageandprematurebearingfailuremayoccurinthe
compressorbearingsifthesystemisnotoperatedonaregularbasisduetovibrationcausedby
truckoperation.
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•Neverattempttocleanthefilterelementwithcompressedair.Replacethefilterelement.
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•Donotattempttochangetheoilfilteruntiltheoilhascooled.Hotoilcancausesevereburns.
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•Neverover‐tightenthefilter,asthismaydamagethesealorthefilter.
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•Useonlythesuppliedcompressoroilinthissystem.Failuretousethisspecialoilwillresultin
damagetothecompressorandwillvoidyourwarranty.
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•Donotoverfillthesystem.Overfillingthesystemwithoilcanfloodthesightglasswindowand
makethesystemappearempty.
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•Ifyouusesolventsforcleaning,thoroughlyrinsethepartswithhotwatertoremoveallsolvent
residues.
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•Checktheinsideofthetankforanyevidenceofmetalfilingsorcontamination;iffound,flush
thetank,hosesandcooler.Metalfilingswilldamagethecompressor.
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Maintaining
VR70andVR140
UNDERHOOD
AirCompressors

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5
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MaintainingtheVRSystem
Organizedmaintenancepracticeswillincreasethelifeexpectancyofthecompressorsystemand
maintainoperationwithinthemanufacturedparameters.VMAChasrecommendedserviceintervalsfor
theirsystemthatisbasedonactualtestingandperformance.TheVRsystemrequiresregular
maintenancethatincludes:
•inspectingandreplacingthedrivebelt
•changingsystemoil
•changingfilters
•cleaningfilterscreens
DuringthewarrantyperiodyoumustfollowthemaintenancescheduleandonlyuseoriginalVMAC
replacementpartstomaintainthesystemandthewarranty.Periodicmaintenanceservicekitsare
availablefromVMAC.
Themostcriticalaspectofcompressoroperationisproperairfiltration.Contaminationenteringthe
intakecancausesevere,rapiddamagetorollerbearings,gearsandrotorsinthecompressor.
Neveroperatethetruck,thecompressororevenallowthetrucktoremainparkedwithoutthe
recommendedairfilterandcoverinstalledonthecompressor.
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Performingapre‐serviceinspection
Inspectthesystemcarefullyandcheckthefollowing:
•lookforleaksatthecompressor,cooler,tank,filterandlinefittings
•checkthecompressorandbrackettomakesurethattheyaretightandsecure
•checkthecoolertomakesurethatitistightandsecure
•checkthetankbracketsandtankmountingtomakesurethattheyarenotloose
•checkallfastenersforevidenceofmotionorvibrationloosening
•examineallthelinesforevidenceofrubbing,chafingorotherenvironmentaldamage
•usingtheappropriatetools,checkallthelinefittingstomakesurethattheyaretight
•checkelectricalconnectionsforsecurity
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•checkallwiringforsecurityanddamage
•checkthecontrolunitstomakesurethattheyaresecure
Ifyoudiscoveranyproblems,performthenecessaryrepairstopreventfurtherdamage.Protectall
wiring,lines,connectionsandfittingsasrequired.Tightenanyloosefastenersandreplaceanydamaged
fastenersorcomponents.
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PeriodicMaintenance
Themaintenancescheduleforthesystemisshowninthefollowingtable.Thehoursshownonthetable
arethosedisplayedonthecontrolpanelread‐out.Serviceshouldbeperformedatthelesserofthetwo
intervals,whicheveroccursfirst.Followingthisprocedurewillensureoptimumperformanceandlong
lifefromtheVRsystem.
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Theseserviceintervalsarebasedonnormaloperation.Commonsenseandgoodmaintenancepractices
willindicatewhethertheseproceduresshouldoccurmorefrequently.Forexample,ifthetruckis
continuouslyoperatinginanextremelydustyenvironment,theairfilterandbeltshouldbeinspected
morefrequently.Sincethecompressordrawsinlargequantitiesofairduringoperation,thefiltermay
becomepluggedandwillaffectoperation.
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InspectingtheDriveBelt
Periodicinspectionofthedrivebeltisnecessarytoidentifypotentialproblemsbeforetheycausefailure
ordamage.WhileVMACrecommendsa50hourinterval,iftheoperatingenvironmentissevere,you
shouldinspectthebeltmorefrequently.
Checkthebeltcarefullyforsignsofglazing,missingportionsoftheribsordamagetotheedgesor
surface.Ifthereisdamage,itmayindicateaproblemwithpulleyalignmentorimproperusebythe
operator.Installinganewbeltwillnotcorrecttheproblem,itwilljustresultindamagetothenewbelt.
Abeltthatisheat‐damagedindicatesthatthebeltisslippingonthecompressororcrankshaftpulleys.
Thismaybecausedbyadefectivetensionerorbytheoperatorengagingthecompressorwhilethereis
pressureinthesystem.Thiscancausethecompressorclutchtostallandthebeltwillslip.Ifthe
tensionerisapplyingsufficientpressureandismaintainingbelttensioncorrectly,talktotheoperator
andfindouthowtheyareusingthesystem.Inspecttheidlers,pulleysandtensionerfordamage.Any
componentthatshowschips,cracksorotherphysicaldamageshouldbereplaced.
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Ifthebeltisdamagedorwornalongtheedges,itcouldindicateanalignmentproblem.Ifthisoccurs,
checkthealignmentofallpulleys,idlersandtensionerswithastraightedge.Ifthereisanalignment
problem,checkallsystemfastenerstomakesurethattheyaretight.Alsocheckforcrackingordamage
onthemountingbracketandatthecompressor.
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7
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InspectingandReplacingtheAirFilter
Properairflowintothecompressorisvitallyimportantforgoodperformance.Ifthefilterbecomes
plugged,thecompressorwillnotbeabletomeetthedemandsandwillprobablyoverheat.While
VMACrecommendsthatyoureplacethefilterevery200operatinghoursortwiceayear,youshould
replacethefiltermorefrequentlyinsevereoperatingconditions,whereitcouldbecomecontaminated
morequickly.
Tocheckthefilter,followthisprocedure:
1.Makesurethatallairpressurehasbeenventedfromthesystem.
2.Cleantheareaaroundthecompressorandfiltercover.
3.Removethefiltercoverretainingnut,thecoverandthefilterelement.
4.Immediatelycovertheopeningofthecompressorwithaclean,dryclothorwithmaskingtoprevent
contaminationfromenteringthecompressor.Donotoperatethetruckorthecompressoruntilthefilter
andcoverhavebeeninstalled.
5.Cleantheinsideofthefiltercoverwithaclean,drycloth.Ifnecessary,youcanusesolventtoclean
theinsideofthecover.Ifyouusesolvent,makesurethatyourinsethecoverwithwateranddryit
thoroughlybeforeinstallingitonthecompressor.Solventfumesenteringthecompressorcouldignite
duringthecompressionprocess,causinganexplosion.
6.Examinethefiltercarefullyforcontamination.Placeatrouble‐lightontheinsideofthefilterand
rotateitoverthelightwhileexaminingtheelement.Theamountoflightthatshinesthroughthe
elementisagoodindicatorofhowmuchaircanpassthroughtheelement.Ifthelightisdimorblocked,
airwillnotbeabletogetthrough.
7.Ifthefilterisdirty,removetheclothormaskingandinstallanewfilter.Donotattempttowashor
blowthefilterelementclean.Thesearenotserviceablefilters,theymustbereplaced.Using
compressedairtocleanafilterelementwilldamagethematerialandallowcontaminationtoenterthe
system.
8.Replacethecoverandthecovernut.Becarefulnottoovertightenthenut.
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8
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CompleteMaintenanceoftheVRSystem
Completesystemmaintenanceshouldbeperformedonceeachyearorevery400systemoperating
hours,whicheveroccursfirst.Again,aswithpreviousserviceitems,youmayhavetoservicemore
frequentlyinsevereoperatingconditions.
Completemaintenancenotonlyincludesreplacingoilandfilters,italsoincludesacompleteinspection
ofthesystem.Thiswillensurethatthesystemcontinuestoprovideoptimumperformanceandwill
extendthelifeexpectancyofthecomponents.
Forbestresults,followthesestepsforservicing:
1.Performacompletepre‐serviceinspectionofthesystem.
2.Replacetheairfilter
3.Draintheoilfromthesystem
4.Replacetheoilfilter
5.Replacethecoalescingseparatorandcleanorreplacethescavengefilter
6.Fillthesystemwithoilandcheckoperation
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ReplacingtheAirFilter
Followtheproceduresoutlinedpreviouslyforairfilterreplacement.
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DrainingOilfromtheSystem
Theoilshouldbedrainedfromthesystembeforechangingfiltersorcleaningthescavengefilter.Make
surethatyouhaveasuitablecontainerthatwillholdapproximately2gallons(US)beforeyoubegin.
Whendrainingtheoil,followthisprocedure:
1.Makesurethatallairpressureisventedfromthesystem.Ifthereisanypressureinthesystem,you
couldbeinjuredwhenyouremovethedrainplug.
2.Placethedraincontainerunderthetankbelowthedrainplug.
3.Usingthecorrecttool,removethedrainplugfromthetank.Becarefulwhendrainingthetank.Ifthe
systemwasoperatedrecently,theoilmaybeveryhotandcancauseburns.
4.Cleanthedrainplugthreadsandinspectthemfordamage.
5.Cleanandinspectthethreadsinthetank.
6.Installandtightenthedrainplugsecurely.
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ReplacingtheOilFilter
Cleanlubricatingoilisvitalforefficientoperationandforpreventingdamagetocomponents.Replacing
theoilfilteratregularintervalswillhelpkeepcontaminantsoutofthecompressorandtherestofthe
system.Whenreplacingtheoilfilter,rememberto:
•makesurethatthereisnopressureinthesystem
•useaproperfilterwrench
•neverover‐tightenthefilter
•checktheoillevelafteroperatingthesystem
•checkforoilleaksafterservice
Toreplacetheoilfilter,followthisprocedure:
1.Cleantheareaaroundthefiltertopreventcontamination.
2.Removethefilterbyturningitcounter‐clockwise.Makesurethatyoudraintheoilfromthefilterinto
asuitablecontaineranddisposeofthefilterandoilaccordingtolocalregulations.Beforeyoudisposeof
thefilter,checktomakesurethatthethreadednippledidnotunscrewwiththefilter.Ifthenippleisin
thefilterratherthaninthecompressor,tankorremotemount,removeitcarefullytopreventthread
damageandreplaceitinitsoriginallocation.
3.Checkthesealingsurfaceonthecompressor,tankorremotemounttomakesurethatitiscleanand
smooth.
4.Applyalightcoatingofcompressoroiltothegasketonthenewfilter.
5.Spinthefilteronthethreadednippleuntilthegasketcontactstheseat.
6.Tightenthefilteranadditional¾to1fullturntoprovideagoodseal.
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ReplacingtheCoalescingSeparatorandScavengeFilter
Toperformthispartoftheservice,youmustremovethebackcoveronthetank.Beforeattemptingto
replacethecoalescingseparatorandscavengefilter,alwaysmakesureofthefollowing:
•thereisnopressureinthesystem
•theoilhasbeendrainedfromthetank
•thebackofthetankhasbeencleanedtopreventcontamination
•becarefulofhotoil
Whentheseconditionshavebeenmet,followthisprocedure:
1.Cleanthebackofthetanktopreventcontamination.
2.Disconnecttheairoutletline,1/4inchand5/16inchlinesfromthebackofthetank.
3.Removetheboltsholdingthedischargecapfromthebackofthetankandremovethecapandsmall
spring,ifequipped.

Topreventdamagetothetank,removealloftheboltscompletelywhileholdingthe
dischargecapfirmlyinplaceasthecoalescingseparatorelementisspringloadedagainst
thedischargecap.
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10
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4.Removethecoalescingseparatorelement,largespring(andontheVR140,thespringplate)from
insidethetank.Discardthecoalescingseparatorelement.
5.RemoveanddiscardtheO‐ringsealandtherearcapseal.
6.Wipeouttheinsideofthetank
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11
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7.Ifthetankhasasmallspringandthimblescreen,thescreencanberemovedbycarefullypushingit
outoftheoilscavengeholefromtheinsideofthetank.
8.Ifthesystemdoesnothaveasmallspring,thescavengescreenwillbelocatedinsidethetank
coalescingchamberandisretainedbyasmallscrew.
9.Checkthethimblescreenorscavengescreenforcontaminationordamage.Ifcontaminated,cleanas
necessaryandblowoutwithcompressedair.Ifdamaged,replacethethimblescreenorscavenge
screen.
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10.InstallnewO‐rings(includingthesmallO‐ringfortankswiththeinternalscavengescreen)andrear
capseal.
11.ThoroughlycleanthelargespringandthespringplateonVR140systems.Removeanyrustor
contaminants.
12.Installthelargespring(withspringplateon140systems–taperedendawayfromthefilter)anda
newcoalescingseparatorelement.Makesurethatthespringisinplace,asitholdsthecoalescing
separatorelementtightagainsttherearcapseal.
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Thelargespringalsoprevents
electrostaticbuildupbygrounding
thecoalescingseparatorelement.
Ifthespringisnotinstalled,an
electricarcmayoccur,whichcould
resultinanexplosion,potential
tankruptureorfire.
Thecoalescingseparatorelement
servicekitmayincludeawave‐type
spring(Figure6.1).Replacethelarge
coilspringwiththewavespringand
discardthecoilspring.
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13.Installthedischargecapandtorquetheboltstospecifications.
14.Installthelinesonthebackofthetank.
15.Removethefillerplugfromtheairinletcontrolvalve.

Ifyouusesolventsforcleaning,
thoroughlyrinsethepartswith
hotwatertoremoveallsolvent
residues.

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16.Pourcompressoroilintotheoilfillerholeontheinletcontrolvalveusingafunnel.
17.Turnthecompressorclutchclockwisetospeedthefillprocess.
18.Allowfiveminutesfortheoiltodrainintothetank,thencheckthelevelatthesightglassatthe
frontofthetank.Continueaddingoiluntiltheleveliscorrect.
19.Installthefillplugintheinletcontrolvalveandtightenitsecurely.
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FillingtheSystemwithOil
1.Removethefillplugfromtheinletvalveonthecompressor.
2.Usingafunnel,pouroilintothecompressorwhileturningthecompressorinaclockwisedirection
usingthehexheadcapscrewatthecenterofthecompressorclutchassembly.
3.Atregularintervals,checktheoillevelatthesight‐glassuntilitreachesthespecifiedlevel.
4.Replacethefillplugortheinletcontrolvalve.
5.Performaquickinspectionofthesystemtomakesurethatalllinesareonandtightandthatthefilter
istight.
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CompletingtheService
1.Placethemanualtransmissioninneutralortheautomatictransmissioninparkandfullyapplythe
parkbrake.
2.Starttheengineandallowittoreachoperatingtemperature.
3.Turnthecompressorswitchonthecontrolunittothe“ON”position,allowthesystemtopressurize
andreturntopresetbaseidlespeed.
4.Turnthecompressorswitchonthecontrolunittothe“OFF”position.
5.Allowthesystemtosettleforfiveminutes,andthenchecktheoillevelthroughthesightglass.The
levelmustbebetweentheminimumandmaximumlevelindicators.
6.Checkforoilleaks.
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