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Cooling system

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Cooling System Features• Thecoolantpumpcanbeservicedwithoutdisconnecting

radiatorhoses.

• Boththeglowplugsleevesandtheinjectorsleevesarestainlesssteel.

Cooling System Features

•CoolantPump

•StainlessSteelInjectorSleeves

•StainlessSteelGlowPlugSleeves

Internal Coolant Flow

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Cooling system

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EGR Cooler #1

Radiator

DegasBottle

Heater Core

EGR Cooler #2

Coolant feedto EGR valve

Hot coolantfrom pump to top radiator port

Cooled coolantto pump frombottom radiator port

Radiator fill/ Overflow supplyto degas bottle (flow in either direction)

Coolant Pump

Color change indicatescoolant temperatureas heat is transferedfrom exhaust gasesto the coolant

Hot exhaust in from rightup-pipe

Partially cooledexhaust gases

Cooled exhaustout to EGR valve

Ho

t C

oo

lan

t

Cooled Coolant

Deaeration/coolant feedto degas bottle

Cooling System Flow: External Flow• Coolantisdrawnintotheinletofthefrontcoverfromthebottom

radiatorportandthenflowsfromthecoolantpumpthroughthefrontcovertothecrankcase.

• Coolantisalsoroutedfromthefrontcoverintothecrankcasetoapassagethatfeedstheoilcooler(shownonnextpage).

• CoolantisroutedfromthefrontcovertotheEGRcoolers,EGRvalve,degasbottle,andthevehicleheatercore.

• ThehorizontalEGRcoolerreceivescoolantfirst,thenthecoolanttravelstotheverticalEGRcoolerthroughashortconnectionhose.HotcoolantexitstheverticalEGRcooleratthetopandentersintothefrontcover.

• AportnexttothehotEGRreturnportinthefrontcoverrouteshotcoolanttotheheatercoreforvehicleheating.ThecoolantthentravelstoaY-pipewhereitmeetswithdegasreturncoolantbeforebeingsentintothefrontcover,justabovethemaincoolantinletfromtheradiotor.

External Coolant Flow

• TheEGRvalvereceivesitscoolantfromapassageatthetopoftheverticalEGRcooler.OncethecoolantexitstheEGRvalveitissenttothedegasbottle(thispassageisthehighestpointinthesystemandisalsothedeaerationport).

• TheportdirectlybelowtheEGRvalvereturn/deaerationportonthedegasbottleisusedasaradiatorfill/overflowlineconnectingwiththetopoftheradiator.

• Adualthermostatsytemisusedtocontroltheflowofreturncoolanttotheradiator.Ifthethermostatsareopen,coolantflowstotheradiatortobecooled.Thebottomthermostathasabypasscircuitthatwillallowcoolanttoreturntothepumpwhenthethermostatsareclosed(speedingenginewarmup).

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Cooling system

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Cooling System Flow: Oil Cooler• Coolantisdirectedoutofthecrankcaseandintotheoilfilterbaseat

thefrontoftheengine.

• Theoilfilterbaseroutesthecoolantdownintothefrontoftheoilcoolerthentowardtherearoftheengine.

• Oncethecoolanthaspassedthroughtheoilcooleritisrouteduptothetopoftheoilcoolerthendirectedtowardsthefrontthroughaportwhereitisthenrouteddown,outofthecooler,throughaportintheblock.

Coolant Inlet from Crankcase

Inlet toCooler

Coolant Outlet to Crankcase

Outletfrom Cooler

Oil Cooler Cover(Top View)

Oil Cooler Cover(Bottom View)

Oil Cooler Cover

Oil Filter Base

Oil Cooler

Oil Cooler Coolant Flow

Cooling System Flow: Back of Front Cover• Coolantissealedviaametalonepiecegasketandis

directedoutofthefrontcoverthroughthree(3)passages.

• Twoofthepassagesroutecoolanttothecrankcasetocoolthecylinderwallsandcylinderheads(therearedifferentsizedorificespressedintothecrankcaseinthesetwopassages).

• Thethirdpassageroutescoolanttotheoilcoolerviaapassageinthecrankcase.

• Therearetwopassagesforcoolanttoreturnfromthecrankcaseintothefrontcover.

COOLANT IN(from block)

COOLANT OUT(to block)

Coolant Orifices

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Cooling system

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Cooling System Flow: EGR Coolers• Cooledcoolantflowsoutofthesupplyportofthefront

coverwhereitisroutedtothehorizontalcoolerattheleftrearsideoftheengine.

• Thecoolantthenexitsthehorizontalcoolerandisimmediatelyroutedintotheverticalcooler.Thecoolantthenexitstheverticalcoolerwhereitisroutedtothereturnportinthefrontcover.

• ThereisasmallportatthetopoftheverticalcoolerwherecoolantisallowedtoflowtotheEGRvalve,coolthevalve,thenthecoolantisroutedtothedegasbottle.Thisportisalsousedasthedeaerationport.

• CoolantflowsthroughtheEGRcoolersandremovesheatfromtheexhaustbeforetheexhaustarrivesattheEGRvalve.

Coolant Pump & Front Cover• Thecoolantpump,(hubandimpeller)ismountedintothe

frontcoverwhichisthehousingforthewaterpump.

• Thecoolantpumpimpellerpullscoolantfromthecenterofthehousingandpushesitoutward.

• Thecoolantpumphasabuiltinreservoirtocatchsmallamountsofcoolantthatduringnormaloperationoftheenginemayseeppasttheseal.Thiscoolantwillevaporateovertime.

Note:Thecoolantpumpimpellermaybedamagedifdroppedorhitbyahardobject.

Injector Sleeve• The6.4LPowerStrokeusesstainlesssteelinjectorsleeves

tosealcoolantfromtheinjectorandtotransferheatfromtheinjectortothecoolant.

• Theinjectorsleeveisreplaceable.

EGR Cooler Horizontal Coolant Supply

EGR Cooler Vertical Coolant Supplyfrom Horizontal Outlet

EGR Cooler Vertical CoolantOutlet/Returnto Front Cover

EGR Valve CoolantSupply

Injector Sleeve

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Cooling system

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Glow Plug Sleeve• Glowplugsleevesareusedtokeepcoolantfromcomingin

directcontactwiththeglowplugsandtosealcoolantfromthecombustionchamber.

• Theglowplugsleeveisreplaceable.Seeuniqueserviceproceduresortheservicemanualformoredetails.

Degas Bottle • Thedegasbottleislocatedontheleftsideoftheengine

compartmentandispartoftheleftsidebatterytray.

• OneoftheportsonthebottleisattachedtotheEGRvalvecoolantline(whichissuppliedfromthetopoftheverticalEGRcooler).Ifthisportorhoseisblocked,damagecouldoccurtotheEGRcoolersand/ortheEGRvalve.

Glow Plug Sleeve