29901B Jake Detroit[2]

Jacobs Engine Brake™

790/795/797 Series

L A U N A M N O I T A L L A T S N I

Table of Contents Section 1: Introduction

Page 4-5

Housing Identication Engine Identication Special Tools Recommended Torue Values Engine Covers

4 4 5 5 5

Section 2: Engine Preparation Series 60 Engines with DDEC IV & V

6-7

Undercover Wire Harness Installation (Retrot)

6

Section 3: Brake Housing Installation

8-10

Slave Piston Adjustment

10

Section 4: Engine Brake Controls

11

Section 5: Engine Brake Operational Check

12

RockerCoverInstallation

Section 6: Engine Brake Maintenance

13-19

Theor o Operation Exhaust Blowdown Part Identication Control Valve Slave Piston Adjusting Screw Solid Screw Solenoid Valve Master Piston Slave Piston

13 13 14 15 16 16 16 17-18 19



INSTALLL INST ALLLA ATION TIONINST INSTRUCT RUCTIONS IONSFOR FOR790/7 790/795/79 95/797SER 7SERIESJ IESJACOB ACOBSEN SENGINE GINEBRAK BRAKES™ ES™

General Information Theseinstructionsdescribetheinstallationothe Model790/795/797SeriesJacobsEngineBrake™, designedortheDetroitDieselSeries60®engine. Forspecicapplicationinormationandslavepiston clearancesettings,reertotheJacobsEngineBrake orDetroitDieselEnginesApplicationGuide,P/N 4770,whichcanbeoundonwww.jakebrake.com.

Safety Precautions Theollowingsmbolsinthismanualsignalconditions potentialldangeroustothemechanicoreuipment. Readthismanualcareull.Knowwhenthese conditionscanexist.Thentakenecessarstepsto protectpersonnelaswellaseuipment.

THISSyMBOLWARNSOFPOSSIBLE PERSONALINJURy.

Foradditionalinormationonthe790/795/797Series enginebrakes,reertotheSeries60EngineService Manual,P/N6SE483. UseOSHA-approvedcleaningsolventorcleaning parts.Originalpartstobereusedshouldbeinspected orwearandreplacedasreuired.Besuretocoat partswithcleanengineoilwhenreinstallingthem. ThestandardJacobsVehicleSstemsWarrant appliestotheinstallationoaJakeBrake ®Kit.The warrantisadministeredbDetroitDieselCorporation. ForspecicwarrantcoveragespleasecontactDetroit Diesel.

THISSyMBOLREFERSTOPOSSIBLE EqUIPMENTDAMAGE.

NOTE:

INDICATESANOPERATION,PROCEDURE ORINSTRUCTIONTHATISIMPORTANTFOR CORRECTSERVICE.

Fuels,electricaleuipment,exhaustgasesand movingenginepartspresentpotentialhazards thatcouldresultinpersonalinjur.Takecarewhen installingeuipmentorparts.Alwaswearsaet glasses.Alwasusecorrecttoolsandollowproper proceduresasoutlinedinthismanual.

NOTE: THEJACOBSENGINEBRAKEISAVEHICLE

SLOWINGDEVICE,NOTAVEHICLESTOP PINGDEVICE.ITISNOTASUBSTITUTEFOR THESERVICEBRAKINGSySTEM.THEVEHICLE'SSERVICEBRAKESMUSTBEUSEDTO BRINGTHEVEHICLETOACOMPLETESTOP.

 NOTE: NEVERREMOVEORADJUSTANyENGINE BRAKEORCOMPONENTWITHTHEENGINE RUNNING.

INSTALLATION INSTRUCTIONS FOR 790/795/797 SERIES JACOBS ENGINE BRAKES™

3

Section 1: Introduction HousingIdentifcation

EngineIdentifcation

Themodel,partnumber,serialnumber,andadjustmentinormationarelocatedonthenameplateatthe topoeachhousing.(SeeFig.1andFig.)

Enginemodelidentication,serialnumberandmodel number,areonthenametaglocatedonthesideo thevalvecoverandstampedontheclinderblock beneaththeintakemaniold.(SeeFig.3)

Fig1

Fig3

Fig

4

INSTALLLATIONINSTRUCTIONSFOR790/795/797SERIESJACOBSENGINEBRAKES™

SpeciaToos

EngineCovers

Genera

Theenginebrakehasbeendesignedtotonthe Series60enginewithnoadditionalvalvecovers.On engineseuippedwithatwo-piecealuminumvalve cover,itisNOTnecessartoremovethelowervalve covertoinstalltheenginebrake.However,onestle uppervalvecovermareuiremodicationatthe breatherhousinglocation(inside)orenginebrake clearance.

18mm-1pointSocket 10mm-1pointSocket 6"Extension 13mmWrench RetainingRingPliers(.047"diameter,45˚) DiagonalWireCutter

KentMoore Rocker ShatLitingTool Stud Torue Socket MasterPistonAssemblTool (Model797Onl)

P/NJ-35966A P/N J-44706A P/NJ-45976

DetroitDiese Series60EngineServiceManual

Jacobs Feeler Gage, 0.00" (0.508 mm) Feeler Gage, 0.06" (0.660 mm) Feeler Gage, 0.03" (0.813 mm) ControlValveCoverRemovalTool

P/N 01778 P/N 017671 P/N 030504 P/N016978

RecommendedTorque Vaues HousingHold-down Cap Screws

Solenoid Valve SlavePistonSpring Shoulder Bolt

NOTE: IFINTERFERENCEEXISTSBETWEENTHE

FRONTENGINEBRAKEHOUSINGANDTHE ROCKERCOVERCAPATTHEBREATHER HOUSINGLOCATION,GRINDTHEUPPER COVERTOPROVIDECLEARANCE.CLEAN COVERTHOROUGHLyAFTERGRINDING.

80 lb.-t. ( 108 N-m) (lubricatedwithengineoil)

RockerShatHold-downStud SlavePistonAdjusting Screw Locknut

Fig4

100lb.-t.(136N-m)

336 lb.-in. (38 N-m) 110 lb.-in. (1.4 N-m)

00 lb.-in. (3 N-m)


5

Section 2: Engine Preparation Series 60 Engines with DDEC IV & V AccessEngineOverhead 1. DisconnectBatter

c.Disconnect10pinwiresocketlocatedon intakesideoclinderblockbelownumber six(6)intakeport.(SeeFig.6)

FAILURETODISCONNECTBATTERyMAy CAUSEECMDAMAGE.

. Thoroughlcleanengine 3. Removevalvecoverandgasket. NOTE: IFTHEENGINEHASATWO-PIECECOVER, THELOWERVALVECOVERBASEDOESNOT HAVETOBEREMOVED.

ExchangeWireHarness 

Fig6

1. Removeexistinginjectorharness&mounting clipsromclinderhead. a.Separatewireharnessromclinderhead retainingclips. b.Removeharnessmountingboltsromrear oclinderheadatheadpassthroughholes. (SeeFig.5)

d.Removeharnessbmanipulatingharness throughclinderheadpassthroughatrear ohead. e.Removeharnessretainingclipsrom threadedholesinheadanddiscardclips. (SeeFig.7)

 

Fig5  NOTE: FORADDITIONALACCESSTOREAR CyLINDERHEADPASSTHROUGH,THE ROCKERSHAFTSMAyBEREMOVED USINGKENTMOORETOOL#J35996A

6

Fig7 NOTE:

REMOVEENTIRECLIPS,HOLESWILL BERE-USEDFORJACOBSSUPPLIED HOUSINGHOLDDOWNBOLTS


. InstallnewharnessP/N3536019oronhighwaapplicationsorP/N353444or o-highwaapplications a.Manipulateharnessthroughrearheadpass through.Routeharnessconsistentto previousharness.

b.Connectnewharnesstoinjectors. c.Connect10pinwiringsockettomainengine harnessandsecureharnesswithplastic wiretiesasnecessartobrakespacer tubes(reerenceFig11inSection3or image). d.Secureharnessatrearheadpassthrough withmountingbolts.

HARNESS IS NOW READY FOR JAKE BRAKE INSTALLATION

Fig8

TAKECARENOTTODAMAGEWIRINGORCONNECTORS


7

Section 3: Brake Housing Installation InstaEngineBrakeHousings 1. RemoveRockerShatAssembliesusing18mm SocketandKentmoore#J-35996A

3.Setront&rearJakeBrakehousingson rockershatslocatingonretoruedstuds. Ensurethatmasterpistonpushrodswillengage withpocketlocatedontopoinjectorrocker arm(seeFig.10).

REMOVINGTHEOILFROMTHEBOLTHOLES PREVENTSTHECyLINDERHEADFROM CRACKINGWHENBOLTSARETIGHTENED. ATTACHALENGTHOFTUBINGTOANAIRGUN  NOZZLEANDBLOWOUTTHEOILFROMTHE ROCKERSHAFTHOLD-DOWNBOLTHOLES. COVERTHEHOLESWITHHANDTOWELSTO MINIMIZEOILSPRAy NOTE:

WEARSAFETyGLASSESWHILE BLOWINGTHEOILFROMTHEBOLT HOLES.

Fig10 a.Removerockerarmholddownbolts M1x100mmlong(6). b.Removerockerarmnutsatrontandrearo head().

4.PositionJakeBrakemountingspacertubes underouterhousingmountinglegs.(SeeFig. 11)

c.Retoruerockershatstudslocatedatront andrearoclinderheadat100lb.-t.(136 N-m)withKentmooretool#J-44706A.(See Fig.9)

NOTE: TOPREVENTDAMAGETOWIREHARNESS,RUN WIRESINBOARDOFSPACERTUBESAND SECURETOTUBESUSINGPLASTICWIRETIES.



Fig9 .SetRockerShatAssembliesbackoncam caps.

8


Fig11

5. InstallJacobssuppliedmountingbolts, twolengths,andoriginalDDCstudhexnuts removedearlier.(SeeFig.1)

6. Toruedownbrakehousingperseuence inFig.14at80lb.-t.(108N-m).

A

B Fig1 A-M1x140mm-usedontheexhaustsideothe engine B-M1x170mm-usedonintakeside(solenoid side)oengine

Fig14 7.Veriexhaustandintakevalvelashisstillwithin DDCspecicationsorengine.Ivalvelash isoutotolerance,reertoDDCmanualor resettingprocedure. 8.Attachsolenoidwirestosolenoidandengage wiresinwireretainerclip.(SeeFig.15)



BEFORETORqUINGENSURETHAT WIREHARNESSISINBOARDSOASTO  NOTE: NOTINTERFEREWITHVALVECOVER

BEFORETIGHTENINGHOLDDOWN BOLTS,MOVETHEHOUSINGFROM NOTE: SIDETOSIDEANDTHENLOCATE HOUSINGINCENTEROFTRAVEL.(SEE FIG.13)

Fig15

NOTE:

797BAPPLICATIONSUTILIZEADDC WIREHARNESSTRAyWHICHISAT TACHEDONTOTHEREARBRAKE HOUSING. REFERENCETHEDDCSERIES60 ENGINESERVICEMANUALP/N6SE483 FORPROPERTRAyTORqUINGPROCEDURE

Fig13


9

Adjust Slave Piston Clearance

FAILURETOFOLLOWADJUSTMENT PROCEDURESCANRESULTINENGINE ORENGINEBRAKEDAMAGE.

NOTE:

MAKESLAVEPISTONADJUSTMENTWITH THEENGINESTOPPEDANDCOLD.ADJUST EACHCyLINDERWITHTHEEXHAUST VALVESINTHECLOSEDPOSITION.

NOTE:

REFERENCEJACOBSAPPLICATIONGUIDE P/N4770FORPROPERENGINEAND BRAKESPECIFICLASHSETTINGS.

MODEL 790 SERIES 1.Backouttheadjustingscrewsontheslave pistonsuntiltheslavepistondoesnottouchthe rockerarmadjustingscrew. . Insertthepropereelergage(correctadjustment isonhousingdatatag)betweentheslave pistonandtheexhaustrockeradjustingscrew. Usinga3/16"(inch)hexwrench,turninthe adjustingscrewuntiltheslavepistoncontacts theexhaustrockeradjustingscrewthroughthe eelergage.Continueturningintheadjusting screwuntilthevalvespringsbegintocompress, thenturninone(1)additionalturn.Waitatleast 30secondsoroiltobepurgedromtheJ-Lash adjustingscrew. NOTE:

4. Rechecklashsettings.Ilashsettingis incorrect,repeatsteps(1)through(3)above ONCETHEENGINEBRAKEHASBEENRUN  NOTE: yOUWILLNOTBEABLETOCHECKTHEENGINEBRAKEADJUSTMENT.THISISBECAUSE OFOILRETAINEDINTHEJ-LASHADJUSTING SCREW.IFUNSUREOFTHEADJUSTMENT, yOUMUSTREPEATSTEPS(1)THROUGH(4) ABOVE.

MODEL 795/797 SERIES 1. Backouttheadjustingscrewsontheslave pistonsuntiltheslavepistonsdonottouchthe exhaustrockerarmadjustingscrews. . Insertthepropereelergage(correctadjustment isonhousingdatatag)betweentheslave pistonandtheexhaustrockeradjustingscrew. Usinga3/16"(inch)hexwrenchturninthe adjustingscrewuntiltheslavepistoncontacts theexhaustrockeradjustingscrewthroughthe eelergage,andadragiseltonthegage.

ALLOILMUSTBEPURGEDFROM THEJ-LASHADJUSTINGSCREW.IFOILIS BELOW60°F,16°C,WAITATLEASTTWO MINUTESFOROILTOBEPURGEDFROM THEJ-LASHADJUSTINGSCREW. SERIOUSENGINEDAMAGEMAyOCCUR FROMIMPROPERLASHSETTING.

3. Aterthetimeintervalspeciedinstep(),back outtheadjustingscrewONLyuntilalightdrag iseltontheeelergage.Donotretractmore than required to obtain a light drag on the feeler gage. Hold the J-Lash adjusting screw

inplaceandtoruethelocknutto38N•m(336 lb-in). NOTE:

Fig16 3. Holdtheadjustingscrewinplaceandtorue thelocknutto38N•m(336lb-in).Recheck lashsettings.Ilashsettingisincorrect,repeat steps(1)through(3)above.

IFTHEJ-LASHADJUSTINGSCREWIS BACKEDOUTUNTILITNOLONGER COMPRESSESTHESLAVEPISTONSPRING, OILWILLENTERTHESCREWANDTHE ADJUSTMENTWILLBEINCORRECT.IFTHIS OCCURS,REPEATSTEPS(1)AND(). OVERTORqUEOFLOCKNUTWILL PROHIBITPROPERJ-LASHOPERATION

10


Section 4: Engine Brake Controls Series 60 Engines with DDEC IV & DDEC V Jacobs Dash Switch (optional) (mauseinplaceoVOEMswitch)

 

ONSERIES60ENGINESEqUIPPEDWITH DDECIVORV,THEENGINEBRAKEIS CONTROLLEDByTHEDDECECM.USEOF AJACOBS'SUPPLIEDCONTROLMODULE ISNOTREqUIRED. CONTACTyOURVEHICLEOEMWITHyOUR VEHICLESERIALNUMBERFORBILLOF MATERIALSNEEDEDFORINSTALLATION.

1. Locateanareaonthedashorthedashswitch group,JacobsP/N00035,anddrilla"hole. . PasstheloosewiresothevehicleOEMwire harnessthroughthe"holeromthebackto theront 3. Attachthewireharnesstotheswitchterminals ontheswitchgroupp/n00035. 4. Installtheswitchassemblwiththebracket, lockwashersandwingnuts(seeFig.18).

Fig17

DONOTOVERTIGHTENNUTS.SWITCH FAILURECOULDRESULT!

NOTE: CONTACTVEHICLEOEMFORINSTALLATION

DETAILSANDWIRINGDIAGRAMOFTHE WIRINGHARNESSANDINTERFACEWITH DASHCONTROLSWITCH.


11

Section 5: Engine Brake Operational Check Bleed the engine brake housings

Two-piece Rocker Cover Installation

1. Besurewiresareawarommovingparts.

1. Makesurethesealisinplaceintherocker coverbaseandsetthecoverinplaceonthe coverbase.

. Starttheengineandallowtorunoraew minutes. 3. Manuallactivatethesolenoidvalveseveral timestoallowthehousingtobelledwithoil. NOTE: THESOLENOIDVALVEISMANUALLy

ACTIVATEDByDEPRESSINGTHE ARMATUREPINLOCATEDINTHECENTER ONTOPOFTHESOLENOID.

SERIES60ROCKERCOVER

Fig18

Check for proper operation. 1. Manuallactivatethesolenoidvalveandwatch themasterpistonstobesurethearemoving downintothepocketintheinjectorrockerarm. . Watchtheslavepistons.Theshouldmove downtocontacttheexhaustvalverockerarm adjustingscrews.

. Installtheboltwithafatwasher,isolatorand limitingsleeveintothecoverholes. 3. Tightentheboltsto14N•m(10lb-t)inthe seuenceshowninFig.1. 4. Toruetheboltsto7N•m(0lb-t).

3. Checkeachhousingtobesureitisunctioning. 4. Shutdownengine.

Rocker Cover Installation One-piece Rocker Cover Installation

Road Test the Vehicle. 1. Roadtestthevehicle.Theenginebrakeshould comeonwhentheswitchisintheONposition, theclutchisengagedandnothrottleisbeing applied.

1. Installthesealintothegrooveinthecoverand setthecoverinplaceontheclinderhead. . Installtheourretainingboltswithisolatorsand washers. 3. Startingwiththecenterboltsandworking outward,tightentheboltstoN•m(16lb-t). 4. Presstheprotectiveplugsintothetwocenter holes.

1


Section 6: Engine Brake Maintenance TheoryoOperation 3. Theinjectorrockerarmbeginsitstravelasin thenormalinjectionccle,movingthemaster pistonupwardanddirectinghighpressureoil totheslavepiston.Theballcheckvalveinthe controlvalveimprisionshighpressureoilinthe master-slavepistonsstem.

Energizingtheenginebrakeeectivelconverts apower-producingdieselengineintoapowerabsorbingaircompressor.Thisisaccomplished throughmotiontranserusingamaster-slavepiston arrangementwhichopensclinderexhaustvalves nearthetopothenormalcompressionstroke, releasingthecompressedclinderchargetoexhaust.

4. Highpressureoilcausestheslavepistonsto movedown,momentarilopeningtheexhaust valves(F),whiletheenginepistonisnearitstop deadcenterposition,releasingcompressedair totheexhaustmaniold.

Theblowdownocompressedairtoatmospheric pressurepreventsthereturnoenergtotheengine pistonontheexpansionstroke.Theeectothis actionisanetenergloss,sincetheworkdonein compressingtheclinderchargeisnotreturned duringtheexpansionprocess.

5. Compressedairescapestotheatmosphere, completingacompressionbrakingccle.

ExhaustBowdown Reerringtotheschematicdrawingbelow,exhaust blowdownoccursasollows: 1. Theenergizedsolenoidvalve(A)permitsengine lubeoil(B)tofowunderpressurethroughthe controlvalve(C)toboththemasterpiston(D) andtheslavepistons(E). . Oilpressurecausesthemasterpistontomove down,comingtorestintheinjectorrockerarm recess(pocket).

A C

B ENGINE OIL IN

ENGINE OIL OUT

E

E D

F

F

Fig19 INSTALLATION INSTRUCTIONS FOR 790/795/797 SERIES JACOBS ENGINE BRAKES™

13

Fig0 NEVERREMOVEANyENGINEBRAKE COMPONENTWITHENGINERUNNING. PERSONALINJURyMAyRESULT

TheJacobsEngineBrakeistpicallatrouble-ree device.However,inspectionsarenecessarand somemaintenanceisreuired.Usetheollowing procedurestokeeptheenginebrakeintopcondition. Thissectioncovershowtoproperlremove,clean andreinstallenginebrakecomponents.Usean OSHA-approvedcleaningsolventwhenwashing parts.Besuretocoatpartswithcleanengineoil whenreinstallingthem.

PARTS LISTING 1SolenoidValve Seal,SolenoidUpper 3Seal,SolenoidCenter 5MasterPiston 6MasterPistonPushrod 7MasterPistonSpring 8MasterPistonRetainer 9SpiroloxRing(797) 9SnapRing(790/795) 10AdjustingScrewLockNut 11SolidScrew(795/797) 11J-Lash(790) 1SlavePiston 13SlavePistonSpringGroup 17RetainingRing 18Washer 19InnerControlValveSpring 0OuterControlValveSpring 1ControlValve PipePlug 3DriveScrew 4WireHarnessClip 5CapScrew 6CapScrew 7SpacerTube Fig1

14


ControVave

REMOVECONTROLVALVECOVERS CAREFULLy.CONTROLVALVECOVERSARE UNDERLOADFROMTHECONTROLVALVE SPRINGS.REMOVEWITHCARETOAVOID PERSONALINJURy.

5. Washthecontrolvalveswithapprovedcleaning solventPushawirethroughtheholeinthe bottomothevalvetoinsurethattheballcheck isree(seeFig.).Theballshouldlitwithlight pressureonthewire.Itheballisstuckinthe valve,thecontrolvalveshouldbereplaced.Dr thevalvewithcompressedairandwipeclean withapapertowel.

1. Pressdownoncontrolvalvewasherusingthe controlvalvecoverremovaltool,Jacobsp/n 16978torelievespringpressure(SeeFig.1)

Fig

Fig1

. Removeretainingringusingretainingringpliers (SeeFig.1). 3. Slowlremovecoveruntilpressureceases,then removethetwocontrolvalvesprings. 4. Usingneedle-nosepliers,reachintothebore andgraspthestemothecontrolvalve. Removethecontrolvalve.

6. Thoroughlcleanthecontrolvalveboreinthe housingusingcleanpapertowels. 7. Dipthecontrolvalvesincleanlubeoil.Holding thevalvebthestem,guideitintotheborethen allowthevalvetodecendtothebottomothe borebitsownweight.Ibindingoccurs,the controlvalveshouldbereplaced.Reassemble partsreversingtheremovalprocedure.Besure retainingringearsarerotated90º(degrees)ater installationtoensureullengagement.

8 INSTALLATION INSTRUCTIONS FOR 790/795/797 SERIES JACOBS ENGINE BRAKES™

15

SavePistonAdjustingScrew

SoenoidVave

MODEl790SERIES

1. Loosentheslavepistonadjustingscrewlocknut andremovetheJ-Lashadjustingscrewrom thehousing.Cleaninapprovedcleaning solvent. . InspecttheJ-Lashassembltoassurethe plungerisretainedinthescrewbod,bpulling ontheplungerwithngers.Theplungershould retractsmoothlandcompletelunderpressure inotreplaceentireassembl. NOTE:AMODERATETOHEAVySPRINGFORCE

WILLBEPRESENTBEHINDTHEPLUNGERIF OILISSTILLTRAPPEDINTHEASSEMBLy.

3. PlacetheJ-Lashassemblintotheslavepiston adjustingscrewboreandreplaceadjusting screwlocknut. NOTE:DONOTEXCEEDLOCKNUTTORqUE.THIS

WILLHINDERPLUNGERMOVEMENTAND CAUSEENGINEBRAKEPERFORMANCE PROBLEMS.

 DONOTDISASSEMBLEORTAMPERWITH THESOLENOIDVALVE.ENGINEDAMAGE COULDRESULT.

1. Disconnectsolenoidvalveharness.Using3/4" socketandextension,unscrewsolenoidvalve. . Removeanddiscardthetworubbersealrings. Itheringsstainthehousingbore,remove withapieceowire. 3. Washoutthesolenoidvalvewithapproved cleaningsolvent.Useabrushtocleantheoil screen.Risethesolenoidvalveincleaning solvent. 4. Cleanoutthesolenoidvalveboreinthe housing.Usecleanpapertowels.Neveruse rags,asthemaleavelintandresiduewhich canplugtheoilpassagewas. 5.Coatnewsolenoidvalvesealringswithclean lubeoil.Installthesealringsontothesolenoid valvebod.Becareulnottotwisttheseal whileinstalling.

Fig3

SoidScrew

Fig4

MODEl795/797SERIES

1. Removethesolidscrews. .Cleanthesolidscrewsinapprovedcleaning solvent.Inspectorexcessivewearordamage. Replaceinecessar.

16

6.Besurethesealsareseatedproperl.Careull screwthesolenoidvalveintothehousing withoutunseatingtheseals.Toruethevalveto 110lb.-in.(1.4N-m).


MasterPiston

MODEl797SERIES

MODEl790/795SERIES

1. Compressmasterpistonretainerandremove snapringusingretainingringpliers(.047" diameter,45˚).(SeeFig.5)

1. Usemechanic'spicktowedgescrewdriver bladebeneathspiroloxring(SeeFig.6).

REMOVESNAPRINGCAREFULLy.MASTER PISTONISUNDERLOADFROMTHE SPRING.REMOVEWITHCARETOAVOID PERSONALINJURy.

Fig6 .Rotatescrewdriverarounddiametertounwind spirolox.Removeanddiscardspiroloxring-it cannotbereused(SeeFig.7).

Fig5

REMOVESNAPRINGCAREFULLy.MASTER PISTONISUNDERLOADFROMTHE SPRING.REMOVEWITHCARETOAVOID PERSONALINJURy.

. Removemasterpistonpushrod,retainer,spring andmasterpiston. 3. Cleanthemasterpistoninapprovedcleaning solvent.Inspectorexcessivewearordamage. Replaceinecessar.Inspectthemasterpiston bore.Somewearmarksarepermissible.Appl cleanlubeoiltothepistonandinsertintobore. Masterpistonshouldmoveinandoutreel withnobinding.Ibindingoccurs,replace masterpistonand/orhousing. Fig7 5. Reassemblethemasterpiston,pushrod,spring, andretainerinhousing.Besuretorotatesnap ring90º(degrees)aterinstallation.  NOTE:THESPRINGSHOULDHOLDTHEMASTER

PISTONCOMPLETELyINTHEHOUSING.IF NOT,THESPRINGHASRELAXEDANDMUST BEREPLACED. NOTE:THESMALLERDIAMETERENDOFTHE

SPRINGENGAGESTOTHEMASTERPISTON PUSHRODBALLEND.SPRINGMUSTNOT EXPANDOVERBALLEND.

3.Removemasterpistonpushrod,retainer,spring andmasterpiston. 4. Cleanthemasterpistoninapprovedcleaning solvent.Inspectorexcessivewearordamage. Replaceinecessar.Inspectthemasterpiston bore.Somewearmarksarepermissible.Appl cleanlubeoiltothepistonandinsertintobore. Masterpistonshouldmoveinandoutreel withnobinding.Ibindingoccurs,replace masterpistonand/orhousing.


17

5.Reassemblemasterpiston,pushrod,spring, retainer,andspiroloxringinhousingusing masterpistonassembltoolJ-45976.(SeeFig. 8) NOTE:WHENPLACINGRETAINERINTOBORE

-PARTNUMBERSHOULDBEVISIBLE.

b.Engagemasterpistonassembltoolintobore. Ridgewillengagewithborechamer. c.Pushdownonspiroloxuntilitsnapsintoplace. (SeeFig.31)

Fig8

Fig31

a.Loadspiroloxintotapperedring.(SeeFig.9) NOTE:THESPRINGSHOULDHOLDTHEMASTER

PISTONCOMPLETELyINTHEHOUSING.IF NOT,THESPRINGHASRELAXEDANDMUST BEREPLACED. NOTE:THESMALLERDIAMETERENDOFTHE

SPRINGENGAGESTOTHEMASTERPISTON PUSHRODBALLEND.SPRINGMUSTNOT EXPANDOVERBALLEND.

Fig9

Fig30

18


SavePistons 1. Removeslavepistonshoulderbolts. NOTE:SPRINGPRESSUREWILLBERELEASEDAS

BOLTISREMOVED.THEREWILLBENO SPRINGPRESSUREREMAININGPRIORTO BOLTBEINGCOMPLETELyDISENGAGED.

Fig30

. Removesprings,bridge,andslavepistons. 3. Cleantheslavepistonsinapprovedcleaning solvent.Inspectorexcessivewearordamage. Replaceinecessar. 4.Ensureslavepistonborehasnoburrsorridges, isoremovewithamachinistdeburringtool. Donothonetheslavepistonbore.Removal otoomuchmaterialwillreducebraking perormance. 5. Reassemblecomponents.Torueshoulderbolt 00lb.-in.(3N-m).

OVERTORqUEWILLFRACTUREBOLT.


19

JacobsVehicleSstems EastDudleTownRoad Bloomeld,CT0600 P/N 9901 Rev. B

VisitusontheInternet: www.JAKEBRAKE.COM ©004 Jacobs Vehicle Sstems, Inc.

Printed in U.S.A.

Rev. 1/06

29901B Jake Detroit[2]

Recommend Documents