RENR1271-11 February 2006 Systems Operation Testing and Adjusting 3126B and 3126E Truck Engine BKD1-Up (Engine) G3E1-Up (Engine) DPF1-Up (Engine) 1AJ1-Up (Engine) 8YL1-Up (Engine) CKM1-Up (Engine) CRP1-Up (Engine) 7AS1-Up (Engine) 8SZ1-Up (Engine) 9SZ1-Up (Engine) i01658146 Important Safety Information Mostaccidentsthatinvolveproductoperation,maintenanceandrepairarecausedbyfailuretoobserve basicsafetyrulesorprecautions.Anaccidentcanoftenbeavoidedbyrecognizingpotentiallyhazardous situationsbeforeanaccidentoccurs.Apersonmustbealerttopotentialhazards.Thispersonshouldalso havethenecessary training,skillsandtoolstoperformthesefunctionsproperly. Improper operation,lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Donotoperateorperformanylubrication,maintenanceorrepaironthisproduct,untilyouhave readandunderstoodtheoperation,lubrication,maintenanceandrepairinformation. Safetyprecautionsandwarningsareprovidedinthismanualandontheproduct.Ifthesehazardwarnings arenotheeded,bodilyinjuryor deathcouldoccurtoyouor tootherpersons. The hazards are identified by the “Safety Alert Symbol” and followed by a “Signal Word” such as “DANGER”,“WARNING”or“CAUTION”.TheSafetyAlert“WARNING”labelisshownbelow. The meaning of this safety alert symbol is as follows: Attention! Become Alert! Your Safety is Involved. Themessagethatappearsunderthewarningexplainsthehazardandcanbeeitherwrittenorpictorially presented. Operations that may cause product damage are identified by “NOTICE” labels on theproduct and in this publication. Caterpillarcannot anticipateeverypossiblecircumstancethat mightinvolveapotentialhazard. The warnings in this publication and on the product are, therefore, not all inclusive. If a tool, procedure,workmethodoroperatingtechniquethatisnotspecificallyrecommendedbyCaterpillar isused,youmustsatisfyyourselfthatitissafeforyouandforothers.Youshouldalsoensurethat theproductwillnotbedamagedorbemadeunsafebytheoperation,lubrication,maintenanceor repair procedures that you choose. The information,specifications, and illustrations in this publicationare onthebasis of informationthat was available at the time that the publication was written. The specifications, torques, pressures, measurements,adjustments,illustrations,andotheritemscanchangeatanytime.Thesechangescan affecttheservicethatisgiventotheproduct.Obtainthecompleteandmostcurrentinformationbeforeyou startany job.Caterpillar dealers havethemostcurrentinformationavailable. When replacement parts are required for this product Caterpillar recommends using Caterpil- lar replacement parts or parts with equivalent specificationsincluding,butnotlimitedto,phys- icaldimensions,type,strengthandmaterial. Failure to heed this warning can lead to prema- turefailures,productdamage,personalinjuryor death. RENR1271-11 3 Table of Contents Table of Contents ChargingSystem-Test ........................................ 98 ElectricStartingSystem-Test.............................. 99 EngineOilPressureSensor-Test...................... 100 Exhaust Particulate Filter Diagnostic Module - Systems Operation Section Test ................................................................... 100 PinionClearance-Adjust ................................... 102 GeneralInformation ................................................ 4 PinionClearance-Adjust ................................... 102 FuelSystem ........................................................... 7 AirInletandExhaustSystem ............................... 36 Index Section LubricationSystem .............................................. 40 CoolingSystem .................................................... 42 Index ................................................................... 104 BasicEngine......................................................... 45 ElectricalSystem ................................................. 48 Testing and Adjusting Section Fuel System FuelSystem-Inspect ........................................... 52 AirinFuel-Test.................................................... 53 EngineSpeed-Check.......................................... 54 FindingTopCenterPositionforNo.1Piston........ 55 FuelQuality-Test................................................. 56 FuelSystem-Prime ............................................. 57 FuelSystemPressure-Test................................. 58 GearGroup(Front)-Time .................................... 60 UnitInjector-Test................................................. 60 Air Inlet and Exhaust System AirInletandExhaustSystem-Inspect................. 62 Turbocharger-Inspect.......................................... 65 InletManifoldPressure-Test ............................... 68 ExhaustTemperature-Test.................................. 69 Aftercooler-Test................................................... 69 EngineCrankcasePressure(Blowby)-Test ........ 72 Compression-Test............................................... 73 EngineValveLash-Inspect/Adjust ...................... 73 Lubrication System EngineOilPressure-Test .................................... 76 EngineOilPump-Inspect .................................... 79 ExcessiveBearingWear-Inspect ........................ 79 ExcessiveEngineOilConsumption-Inspect ....... 79 IncreasedEngineOilTemperature-Inspect ........ 80 Cooling System CoolingSystem-Check(Overheating) ................ 81 CoolingSystem-Inspect...................................... 83 CoolingSystem-Test........................................... 84 WaterTemperatureRegulator-Test..................... 88 WaterPump-Test ................................................ 89 Basic Engine PistonRingGroove-Inspect................................ 90 ConnectingRodBearings-Inspect ...................... 90 MainBearings-Inspect ........................................ 90 CylinderBlock-Inspect ........................................ 90 Flywheel-Inspect................................................. 91 FlywheelHousing-Inspect................................... 92 VibrationDamper-Check .................................... 94 VibrationDamper-Check .................................... 95 Electrical System Battery-Test......................................................... 97 4 RENR1271-11 Systems Operation Section Systems Operation Section i02497376 General Information SMCS Code: 1000 g00608514 Illustration1 Rightsideview (1)Liftingeye (6)Belttensioner (2)Enginecrankcasebreather (7)Waterdrainplug (3)Turbocharger (8)Crankshaftvibrationdamper (4)Oilfiller (9)Oilfilter (5)Watertemperatureregulatorhousing (10)Jacketwaterpump RENR1271-11 5 Systems Operation Section g00608515 Illustration2 Leftsideview (11)Oilfiller (14)Fuelprimingpump(ifequipped) (17)Aircompressor (12)Liftingeye (15)Oillevelgauge(typicalexample) (18)Cylinderheadgroundingstud (13)Fuelfilter (16)EngineControlModule(ECM) (19)Oildrainplug The3126Band3126Eenginesarein-linesixcylinder Theenginehasbuilt-indiagnosticsinordertoensure arrangements. The firing order of the engine is thatallofthecomponentsareoperatingproperly.In 1-5-3-6-2-4.Theengine’srotationiscounterclockwise theeventofasystemcomponentfailure,theoperator whentheengineisviewedfromtheflywheelendof willbealertedtotheconditionviathecheck engine theengine.The engineutilizes aturbocharger and lightthatislocatedonthedashboard.Anelectronic anair-to-airaftercooler.Theengineshaveaboreof servicetoolcanbeusedtoreadthenumericalcode 110mm(4.3inch)andastrokeof127mm(5.0inch). ofthefaultycomponentorcondition.Also,thecruise Thedisplacementis 7.25L(442cuin). controlswitchescanbeusedtoflashthecodeonthe checkenginelight.Intermittentfaultsareloggedand Thehydraulicelectronicunitinjectorsystem(HEUI) stored in memory. eliminates many of the mechanical components thatareusedinapump-and-linesystem.TheHEUI Starting The Engine also provides increased control of the timing and increased control ofthe fuel airmixture. Thetiming The engine’s ECM will automatically provide the advance is achieved by precise control of the unit correct amount of fuel in order to start the engine. injectortiming.Enginerpmiscontrolledbyadjusting Do not hold the throttle down while the engine is theinjectionduration.Aspecialpulsewheelprovides cranking.Iftheenginefailstostartintwentyseconds, informationtotheEngineControlModule(ECM)for releasethestartingswitch.Allow thestartingmotor detectionofcylinderpositionandenginerpm. to cool for twominutes before the starting motor is used again. 6 RENR1271-11 Systems Operation Section NOTICE Excessive ether (starting fluid) can cause piston and ringdamage.Useetherforcoldweatherstartingpur- poses only. Cold Mode Operation Starting the engine and operation in cold weather isdependentonthetypeoffuelthatisused,theoil viscosity,andother optionalstartingaids.For more information,refertotheOperationandMaintenance Manual,“ColdWeatherOperation” topic(Operation Section). i01750138 Fuel System SMCS Code: 1250 RENR1271-11 7 Systems Operation Section Introduction g00457847 Illustration3 DiagramofcomponentsfortheHEUIfuelsystem 8 RENR1271-11 Systems Operation Section (1)Unitinjectorhydraulicpump (14)Speed/timingsensors (27)Inletairheaterlamp (2)Oilflowtoengine (15)ECM (28)Fastidlelamp (3)Oilfilter (16)Boostpressuresensor (29)Checkenginelamp (4)Engineoilpump (17)Acceleratorpedal (30)Speedometerandtachometer (5)Oilcooler (18)Acceleratorpedalpositionsensor (31)CruiseON/OFFswitchandCruise (6)IAPsensor (19)Batteries SET/RESUMEswitch (7)Injectors (20)Coolanttemperaturesensor (32)PTOON/OFFswitchandSET/RESUME (8)Fuelsupplyrail (21)Datalink switch (9)Fuelpressureregulator (22)Exhaustbrakerelay (33)Servicebrakeswitches (10)IAPcontrolvalve (23)Inletairtemperaturesensor (34)Neutralandclutchswitches (11)Fuelfilter (24)Transmissionrelay (35)Fueltransferpump (12)Fueltank (25)Vehiclespeedsensor (13)Backofcamgear (26)Inletairheaterrelay The operation of the Hydraulic Electronic Unit The HEUI uses engine lubrication oil that is Injector (HEUI) fuel system is completely different pressurized from 6 MPa (870 psi) to 27.5 MPa fromany other typeoffuel system that is actuated (4000 psi) in order to pump fuel from the injector. mechanically. The HEUI fuel system is completely TheHEUIoperatesinthesameway asahydraulic freeofadjustment.Adjustments tothecomponents cylinder in order to multiply the force of the high that are mechanical can not be made.Changes in pressure oil. By multiplying the force of the high performancearemadebyinstallingdifferentsoftware pressure oil, the HEUI can produce injection inEngineControlModule(ECM)(15). pressures that are very high. This multiplication of pressureisachievedbyapplyingtheforceofthehigh Thisfuelsystemconsistsofsixbasiccomponents: pressureoiltoapiston.Thepistonislargerthanthe plungerbyapproximatelysixtimes.Thepistonthatis • HydraulicElectronicUnitInjector(HEUI)(7) poweredbyenginelubricationoilunderhighpressure pushes on the plunger. This engine lubrication oil • EngineControlModule(ECM) (15) underhighpressureiscalledtheactuationpressure oftheoil.Theactuationpressureoftheoilgenerates • Unitinjector hydraulic pump (1) the injection pressure that is delivered by the unit injector.Injectionpressureisgreaterthanactuation • InjectionActuationPressureControlValve(10) pressureoftheoilbyapproximatelysixtimes. • Fuel Transfer Pump (35) Low actuation pressure of the oil results in low injectionpressureofthefuel.Duringconditionsoflow • InjectionActuationPressureSensor(6) speedsuchasidleandstart,lowinjectionpressureis utilized. Note: The components of the HEUI fuel system arenotserviceable.Thesefuelsystemcomponents High actuation pressure of the oil results in high mustnotbedisassembled.Disassemblywilldamage injection pressure of the fuel. During conditions of the components. If the components have been highspeedsuchashighidleandacceleration,high disassembled,Caterpillarmaynotallow awarranty injection pressure is utilized. claimorCaterpillarmayreducethewarrantyclaim. Therearemanyotheroperatingconditionswhenthe Component Description injectionpressureisbetweentheminimum andthe maximum. Regardless of the speed of the engine, the HEUI fuel system provides infinite control of Hydraulic Electronic Unit Injector injection pressure. TheHEUIfuelsystemutilizesahydraulicallyactuated Engine Control Module (ECM) electronicallycontrolledunitinjector(7). Engine Control Module (ECM) (15) is located on All fuel systems for diesel engines use a plunger the left side of the engine. The ECM is a powerful andbarrelinordertopumpfuelunderhighpressure computer that provides total electronic control of into the combustion chamber. This fuel is pumped engine performance. The ECM uses data from intothecombustionchamber inpreciseamountsin engine performance that is gathered by several ordertocontrolengineperformance.TheHEUIuses sensors. Then, the ECM uses this data in order engineoilunderhighpressureinordertopowerthe to make adjustments to the fuel delivery, injection plunger. All other fuel systems use a fuel injection pressure and injection timing. The ECM contains pump camshaftlobe in order topower theplunger. programmedperformancemaps(software)inorder Because the HEUI is much different, a technician to define horsepower,torquecurves andrpm.This mustusedifferenttroubleshootingmethods. softwareiscommonlycalledthepersonalitymodule. RENR1271-11 9 Systems Operation Section Some engines use Engine Control Modules Fuel transfer pump (35) is a single piston pump (ECM) (15) with a replaceable computer chip. that is spring loaded. The shaft of the unit injector The software has already been installed in the hydraulicpumpprovidespowertothetransferpump replaceablecomputer chip.The 3126B and3126E throughanoff-centerbearing.There aretwocheck diesel truck engines do not have a replaceable valves in the fuel transfer pump. The inlet check personality module. The 3126B and 3126E diesel valveopens inordertoallow fuelfromthetank into truck engine’s personality modulearea permanent the pump. The inlet check valve closes in order partoftheECM.The3126Band3126Edieseltruck to prevent fuel leakage back to the fuel tank. The engine’spersonalitymodulecanbereprogrammed. outlet check valve opens in order to supply fuel to Reprogramming ofthepersonality module requires thefuelsupplypassage.Thefuelsupplypassageis theuseofCaterpillarElectronicTechnician(CatET). locatedinthecylinderhead.Thefuelsupplypassage TheflashfunctionofCatET willbeusedduringthe suppliesfueltoinjectors (7).Theoutletcheckvalve reprogramming. closes inorder topreventpressurizedfuelleakage back through the pump. ECM (15) logs faults of engine performance. Also, the ECM is capable of running several diagnostic Injection Actuation Pressure Sensor tests automatically when the ECM is used with an (IAP) electronicservicetoolsuchastheCatET. IAP Sensor (6) is installed in the high pressure oil Unit injector hydraulic pump manifold. The high pressure oil manifold supplies actuationoilinordertopowertheunitinjectors.The Unit injector hydraulic pump (1) (high pressure oil IAP Sensor monitors injection actuation pressure. pump)islocatedattheleftfrontcorneroftheengine. The IAP Sensor sendsa continuous voltage signal Theunitinjectorhydraulicpumpisapistonpumpthat back to ECM (15). The ECM interprets the signal. hasafixeddisplacement.Theunitinjectorhydraulic TheECMisawareoftheinjectionactuationpressure pumpusesanaxialpiston.Theunitinjectorhydraulic at all times. pumpusesaportionoftheenginelubricationoil.The unitinjector hydraulicpump pressurizestheengine lubricationoiltotheinjectionactuationpressurethat isrequiredinordertopowertheHEUIinjectors. Injection Actuation Pressure Control Valve (IAP Control Valve) Injection actuationpressurecontrolvalve(10) (IAP Control Valve) is locatedonthe sideofunitinjector hydraulic pump (1). Under most conditions, the pump is producingexcessoil flow.The IAP Control Valve discharges excess pump flow to the drain in order to control injection actuation pressure to the desiredlevel.TheIAPControlValveisavalveofhigh precisionthatcontrolstheactualactuationpressure. The performance maps of ECM (15) contain a desiredactuationpressureforeveryengineoperating condition. The ECM sends a control current to the IAPControlValve.Thecontrolcurrentshouldmake the actual actuation pressure equal to the desired actuation pressure. IAPControlValve(10)isanactuator.TheIAPControl ValveconvertsanelectricalsignalfromECM(15)to the mechanical control of aspool valve in order to control pump outlet pressure. Fuel Transfer Pump Fuel transfer pump(35) is mounted on the back of unit injector hydraulic pump (1). The fuel transfer pump is used in order to draw fuel from fuel tank (12). Also, the fuel transfer pump is used in order to pressurize the fuel to 450 kPa (65 psi). The pressurizedfuelissuppliedtoinjectors(7). 10 RENR1271-11 Systems Operation Section HEUI Fuel System Operation Low Pressure Fuel System g00458217 Illustration4 Lowpressurefuelsystem