
IMPORTANT:
It is essential that you and any other operator of this
product read and understand the contents of this manual
before installing and using this product.
SAVE THIS MANUAL FOR FUTURE REFERENCE
USER MANUAL
400P AUTOMATIC PORTABLE COMPRESSOR
HEAVYWEIGHT SERIES
PART NO. 40045

IMPORTANT SAFETY INSTRUCTIONS:
CAUTION: To reduce risk of electrical shock or electrocution:
- Donotdisassemble.Donotattemptrepairsormodications.
Refertoqualiedserviceagenciesforallserviceandrepairs.
- Do not use this product in or area where it can fall or be pulled into water or other liquids.
- Do not reach for this product if it has fallen into liquid.
- Usethiscompressorwith12-voltDCsystemsonly.
- Thisproductshouldneverbeleftunattendedduringuse.
WARNING:Topreventinjury:
- Neverallowchildrentooperatethiscompressor.
Closesupervisionisnecessarywhenthiscompressorisbeingusednearchildren.
- ThiscompressorwillbecomeveryHOTduringandimmediatelyafteruse.
Donottouchanypartofthiscompressorwithbarehands,otherthantheON/OFFswitch
during and immediately after use.
- Donotusethisproductnearamesorexplosivematerialsorwhereaerosolproducts
are being used.
- Donotoperatethisproductwhereoxygenisbeingadministered.
- Do not pump anything other than atmospheric air.
- Neverusethisproductwhilesleepyordrowsy.
- Donotuseanytoolsorattachmentswithoutrstdeterminingmaximumairpressureforthat
tool or attachment.
- Neverpointanyairnozzleorairsprayertowardanotherpersonoranypartofthebody.
- This air compressor is equipped with an Automatic Reset Thermal Protector, and can
automatically restart after the thermal protector resets. Always cut off power source when
thermalprotectorbecomesactivated.
- Wear safety glasses or goggles when operating this product.
- Useonlyinwellventilatedareas.
- Afterusage,alwaysreleaseexcesspressurefromthecoilhosebyturningOn/OffswitchtotheOff
position,disconnecthosefromcompressor,withthetireinationgunstillconnectedtotheother
endofthecoilhose,pulltriggeronthetireinationguntoreleaseexcesspressure.
USER MANUAL
400P AUTOMATIC PORTABLE COMPRESSOR

400P AUTOMATIC PORTABLE COMPRESSOR
OPERATING INSTRUCTIONS:
Pleasereadandfollowtheoperatinginstructionscarefullytoassurethatyouwillenjoythe
convenienceandbestuseoutofyouraircompressor.
1.AlwaysoperatethecompressorATORBELOWTHEMAXIMUMPRESSURERATINGofthe
compressor.RefertoSpecicationssectionofthismanual.
2.AlwaysOBSERVETHEMAXIMUMDUTYCYCLEoftheaircompressor.RefertoSpecications
sectionofthismanualfordetails.Operationsexceedingmaximumpressureratingsandorduty
cycle will result in damage to air compressor.
3.YouraircompressorisequippedwithanAUTOMATICTHERMALOVERLOADPROTECTOR.
Thisfeatureisdesignedtoprotecttheaircompressorfromover-heatingandcausingpermanent
damagetoyouraircompressor.Thethermaloverloadprotectorwillautomaticallycutoffpower
toaircompressorshouldinternaloperatingtemperatureoftheaircompressorriseabovesafe
levelsduringexcessiveuse.
4.Shouldyourcompressorshutoffsuddenlyafterextendeduse,donotattempttorestartair
compressor.TurnON/OFFswitchofaircompressortotheOFFposition.Theautomaticthermal
overloadprotectorwillautomaticallyresetwheninternaltemperatureoftheaircompressordrops
belowsafelevel.Afterallowingaircompressortocooloffforabout30minutes,youcansafely
resume use of the air compressor by turning on the air compressor.
5.Foryourconvenience,andtoprotecttheaircompressorfromover-pressureoperationthatcan
cause permanent damage to the unit - this compressor is equipped with built-in pressure switch
withafactorysetcut-onpressureof120PSI(±5%)andafactorysetcut-offpressureof
145PSI(±5%).Duringinationoftirepressuresbetween115PSIto145PSI,ifyoustopination,
the compressor may not restart. This is completely normal, since inline pressure is greater than
cut-on pressure of the pressure switch and less than cut-off pressure of the pressure switch.
Torestartcompressor,deatetirepressuretobelow115PSI,reconnecttirechucktotirevalve
stemandresumetireination.
6.Pleasenotethatyoumayexperienceaslightdelayofthecompressor’smotorstartingwhenthe
ON/OFFswitchisturnedonwhilecompressorispressurized(whenthereispressureintheline
thatthecompressorisconnectedto).Thisisanormaldelayedreaction,notaCompressor
ON/OFFswitchmalfunction.
7.Itisstronglyrecommendedthatyoukeepthevehicle’senginerunningwhileusingtheair
compressortopreventdischargeofyourvehicle’sbattery.
8.ONLYOPERATETHEAIRCOMPRESSORINWELLVENTILATEDAREAS.
Compressorperformanceisenhancedwhenoperatingcompressorwithvehicleenginerunning.
IMPORTANT:Enginemustberunningwhileusingthiscompressor.
Beforeattachingaircompressorpowerclampstoyourvehicle’sbatteryterminals,checktomake
surethattheON\/OFFswitchofyourcompressorisintheOFFposition.AttachthePositive(+)
batteryclamp(Red)tothePositiveterminalofthebatteryandtheNegative(-)batteryclamp(Black)
totheNegativeterminalofthebattery.Alwayskeepyourvehicle’senginerunningwhileoperating
compressortoavoiddrainingyourvehicle’sbattery.
CAUTION:YourPortableAirCompressorisMoistureandDustResistant,butNOTWATERORDUST
PROOF.Neverplacecompressorinsoftsandwhilerunningthecompressor.Vibrationfromthe
compressor will cause the compressor to settle into soft sand, resulting in compressor drawing in
foreignparticles.Neverexposecompressortowaterwhilerunningthecompressor.
USER MANUAL

OPERATING INSTRUCTIONS (cont’d):
This air compressor comes with 1/4” quick connect stud. An extension coil hose and a tire
ination gun are also included with your compressor. Each end of the extension coil hose is
equipped with a 1/4” quick connect coupler. The tire ination gun comes with a 1/4” quick
connect stud, pressure gauge, rubber hose, bleeder valve and tire chuck. Attach one end of
the extension coil hose to the stud on your compressor and the other end to the stud on the
tire gun kit. The tire gun kit can be used for both airing up and airing down. Please familiarize
yourself with the following functions of this versatile air tool:
TIRE INFLATION:
1.Attachoneendoftheextensioncoilhosetothecompressorandtheotherendtothetiregunkit.
2.Pushthetirechuck,withtheleverintheuprightposition,downoverthetirevalvestemandthen
pushtheleverdowntothehorizontalpositiontolockinplace.
3.Turncompressorswitchonandholddownthetriggeronthetiregunkittobeginination.
4. When desired pressure is reached, release the trigger and turn power switch on compressor off.
CAUTION:Toavoidoverination,neverexceedrecommendedpressureonarticlestobeinated.
Burstingcancauseseriousinjury.
NOTE:Youraircompressorisequippedwithapressureswitch(cutinat120PSI,cutoutat
145PSI).Thisfeatureisdesignedtoprotecttheaircompressorfromover-pressurecausing
permanent damage to your air compressor. The pressure switch automatically turns off the motor
whentheinternalpressureoftheaircompressorreachesthefactoryset“cut-out”pressure(145PSI)
andrestartswhentheinternalpressuredropsbelow120PSI.
TIRE DEFLATION:
1.Pushthetirechuck(withtheleverintheuprightposition)downoverthetirevalvestemand
thenpushtheleverdowntothehorizontalpositiontolockinplace.
2.Pressthebleedervalvebuttononthetiregunkittodecreasetirepressure.
3.Whendesiredpressureisreached,releasethebleedervalvebuttontohaltdeation.
IMPORTANT:Makesurecompressorsitsuprightwhileoperatingcompressor.Donotoperate
compressorinanyotherposition.Avoidtuggingatcompressortomoveit.Instead,move
compressortothesamesideofvehicleastiresthatarebeingairedup.
AlwaysmakesurethePortableCompressor’spowercordisuncoiledandfullyextended
whenusingyouraircompressortoavoidoverheatingthepowercord.
INLINE PRESSURE GAUGE:
1.Thepressuregaugeontheinationgunprovidesconvenienttirepressuremonitoringwhenairing
upordown(notairowofthecompressor).Thiseliminatesswitchingbackandforthbetweena
tire chuck and a tire pressure gauge.
2.Pleasenotethatduringinationanddeation,duetoairvelocity,pressuregaugecannotprovide
accuratepressurereadings.Releaseleveronthetireinationgunduringinationtocheck
tire air pressure.
NOTE:Toreleaseexcesspressure,turnoffcompressoranddisconnecthosefromcompressor.
Withthetireinationgunstillconnectedtotheotherendofthecoilhose,pulltriggeronthetire
inationguntoreleaseexcesspressure.
400P AUTOMATIC PORTABLE COMPRESSOR
USER MANUAL

SAFETY PRECAUTIONS:
1.Alwaysinatetirestomanufacturer’srecommendedtirepressures.Exerciseextremecaution
whendrivingwithaired-downtires.Reinatetiresbeforehigh-speedroadwaytravel.
2.Neverexceed20M.P.H.whendrivingwithpartiallyinatedtires.
3.Nevermakesharpturnswhiledrivingwithreducedtirepressure.
4.Re-inatetiresbeforehighspeedtravelingontoroadways.
5.Useheat-resistant,minimum200PSI-ratedworkingpressureextensionhose.
Donotuseaftermarkethoseswithlessthan200PSIworkingpressure.Someaftermarkethoses
may not be suitable for use with this air compressor due to heat and pressure typically generated
by this type of air compressors.
IMPORTANT:AlwaysuseanOpen-Endedtirechucksuchasthetirechuckequippedonthe
Deator/InatorCoilHosefortireinationwhenusingacompressorwithoutanairtank.
CAUTION:Nevertouchtheaircompressororttingsconnectedtotheaircompressorotherthan
theON/OFFswitchwithbarehandsduringorimmediatelyafteruse.Theextensionhoseandttings
connectedextensionhosewillbecomeveryHOTduringandafteruse.Ifnecessary,wearheat
resistantglovestoremovehosefromthecompressorquickconnectstud.
RECOMMENDATION:
Thiscompressorisequippedwithapoppetpressurereleaseheadvalve.Headpressurewillslowly
decrease(pressurewillbereleasedthroughtheintakeportofthecompressor)toallowsmooth
re-startsunderpressure.Ifcompressor’sishookeduptopowersourceandifthepowerswitch
isleftintheONpositionformorethan7to8minutes,Compressorwillautomaticallyturnonfora
shortduration(3to5seconds)torecoverpressureduetobuilt-inpressureswitch.Thisisanormal
function of the compressor. Always shut off power to the compressor when the compressor is
not in use.
MAINTENANCE & REPAIRS:
Youraircompressorisequippedwithpermanentlylubricated,maintenance-freemotor.
Nevertrytolubricatethecompressor.Regularlycleandustanddirtfromcompressorcoolingns
andmotorhousing.AllrepairsshouldbeperformedbyManufacturerorManufacturerauthorized
serviceagenciesonly.
400P AUTOMATIC PORTABLE COMPRESSOR
USER MANUAL

INLET AIR FILTER INSTALLATION INSTRUCTION:
1.ChecktomakesureairlterelementisproperlyinstalledinyourInletAirFilterAssembly
2.Removethetemporaryprotectiveredplugfromcompressor’sairinletport.
3.Installinletairlterontocompressor’sairinletport.(TeontapeNotRecommended).
4.Handtighteninletairlter.
IMPORTANT:Foroptimalcompressorperformance,replacelterelementperiodically.
Cloggedlterwilldrasticallyreducecompressorowrateandperformance.
400P AUTOMATIC PORTABLE COMPRESSOR
USER MANUAL

TROUBLESHOOTING GUIDE:
Compressorwillnotrun 1. No power, or power switch
inOFFposition
2.Blownfuse
3.Motoroverheats
1.Makesurecompressor
switchisON
2. Disconnect compressor
from power source, replace
fuse.(RefertoSpecications
section for correct
fuseamperage)
3.Letcompressorcoolofffor
about30minutestoallow
thermaloverloadswitchtoreset.
Thermaloverload
protector cuts out
repeatedly
1.Lackofproperventilationor
ambient temperature is too high
2.Compressorvalvesfailed
1.Movecompressortowell
ventilatedarea,orareawith
lower ambient temperature
2. Replace compressor
Excessiveknocking
or rattling
1. Worn bearing on eccentric or
motor shaft
2.Cylinderorpistonringisworn
1.Serviceorreplacecompressor
Compressorairowlower
than normal, or cannot
pump to higher pressures
1.Wornpistonringorinletvalve 1.Serviceorreplacecompressor
PROBLEM: POSSIBLECAUSE(S) CORRECTIVEACTION
400P AUTOMATIC PORTABLE COMPRESSOR
USER MANUAL

LIMITED WARRANTY:
VIAIRCorporationwarrantsthisproduct,whenproperlyinstalledandundernormalconditionsof
use, to be free from defects in workmanship and materials for a period of one year from its original
dateofpurchase.Toreceivewarrantyserviceorrepair,pleasecontactVIAIRCorporation.
Returnsshouldbemadewithinoneyearofthedateofpurchase,afteraReturnGoodsAuthorization
(RGA)numberhasbeenassignedbyVIAIRCorporation.ToobtainRGA,faxacopyofyourreceipt
to(949)585-0188.Forcompletewarrantydetails,pleasevisit:www.viaircorp.com/warranty
PLEASE NOTE:
THISWARRANTYCOVERSPRODUCTDEFECTSONLY;ITDOESNOTCOVERINCIDENTAL
ORCONSEQUENTIALDAMAGESASRESULTOFMISUSEORABUSE.
15EDELMAN•IRVINE,CA92618
TEL:(949)585-0011•FAX:(949)585-0188
www.viaircorp.com
MODEL 400P AUTOMATIC SPECIFICATIONS:
PartNumber: 40045/400PAutomatic
MotorVoltage: 12-volt
MotorType: PermanentMagnetic
Max.IntermittentPressure: 150PSI
Max.DutyCycle: 33%(20on/40off)
(Min.On/Off@72ºF&100PSI)
ContinuousUse@72ºF&30PSI: Approx.40Minutes
Max.CurrentConsumption: 30Amps
Fuse: 40Amps
InlinePressureGauge: 160PSI
Auto.ResetThermalProtection: Yes
400P AUTOMATIC PORTABLE COMPRESSOR
