Tips, Test and Repair Information: Drum Brakes

16. Evacuating air from the brake system

ff Fillfandfbleedfthefbrakingfsystemfusingfthefbleedingfdevice

17. Basic adjustment of the drum brakes

ff Carryfoutfthefbasicfadjustmentfoffthefbrakefshoes.fTofdofthis,factivatefthefbrakef

pedalfseveralftimesfinfsuccessionfuntilfclickingfsoundsfarefnoflongerfheard

18. Parking brake cable assembly

ff Reattachfthefparkingfbrakefcableftoftheftiefrod

Important!

·f Wefrecommendfthatfyouffirstfcleanforfrethreadfandflubricateftheftiefrod.ff

f Thisfwillfmakefthefadjustmentfconsiderablyfeasier.fReplaceftheflocknuts

·f Thefadjustmentfprocessfandfthefnumberfoffnotchesfvaryfdepending

f onfvehicleftype.fVehicle-specificfsettingfinstructionsfcanfbeffoundf

f infESI[tronic]

Important!

·f Thefbasicfadjustmentfoffthefbrakefshoesfisfcarriedfoutfusingfthefautomaticf

adjustmentfdevice.fThisfisfonlyfpossiblefiffthefparkingfbrakefcablesfareffullyf

tensioned.fUnderfnofcircumstancesfshouldfairfgapfadjustmentfbefcarriedfoutf

byftensioningfthefparkingfbrakefcables

15. Brake Drum Assembly

ff Dofnotfapplyfanyflubricants,fpastesforfpaintftoftheff f f f

cleaned,fshiny,fmetallicfsurfacefoffthefwheelfhub

ff Fitfthefbrakefdrum

Important!

·f Brakefdrumsfarefsubjectedftofextremefpressurefdueftoff f

f temperatureffluctuationsfandfenvironmentalfinfluences,ff f

f waterfspray,froadfsalt,fstonesfetc.fWefrecommendfthatff f

f brakefdrumsfarefreplacedfwhenfthefdrumfbrakefisfrepaired

19. Final work stage

ff Refitfanyfdisassembledfheatftransferfplatesfetc.

ff Lowerfthefvehiclefandfsecurefthefwheelfboltsfandfwheelfnuts.f

Keepfanfeyefonftheftorque

ff Testffunctionalityfandfcarryfoutfaftestfrun

Ff0

26

fP0

2f6

32

f/f2

01

11

1fff

fff9

9.9

9.X

X

Brake checklist, 20 safety points

The following testing and control tasks consist of visual, functional and leak checks. They are supplemented by internal examinations and efficiency checks. This may require disassembly and assembly work. The description of disassembly and assem-bly work and further information is available in ESI[tronic].

1. Efficiency test on brake tester

Brakingfforcesf/fdeviationfoffbrakingfforcesf/fdeterminationfoffbrakingffactorf/fobservancefoffspecifiedfvaluesf

For further information, see ESI[tronic]

®fffffff®

2. Test drive

Noisesf/fpulsatingfbrakefpedalf/ftorsionalfvibrationfatfsteeringfwheelf/fsteeringfwheelfnotfinfcenterfpositionf/f

vehiclefpullsftofleftforfright

®fffffff®

3. Wheel bearings

Condition,frollingfnoisesf/ftiltingftolerancef/faxialfclearancef/fsecurity ®fffffff®4. Wheel suspension

Supportingfandfguidingfjointsf/fwheelfhubf/fwheelfsecuringfsystem ®fffffff®5. Axles, suspension, steering

Springfstrutf/fshockfabsorberf/fsuspensionfspringsf/faxlefguidef/frubberfmountingf/fsteering ®fffffff®6. Tires / rims

Treadfdepthf/fwearf/fpressuref/fwheelfbalancingf/fsuitabilityfforfthefvehiclef/fdamage ®fffffff®7. Actuation device for service brake

Pedalfrubberf/ffreefplayf/factuatingfrodfplayf/feasefoffmovementfoffpedalfshaftf/fbrakeflightfswitch ®fffffff®8. Actuation device for parking brake system

Leverfstrokef/fdetentfdevicef/feasefoffmovementf/fdisplayflampf/factuationfdevicefwithfelectromechanicalfFBA ®fffffff®9. Brake booster, non-return valve

Externalfdamagef/fsecuringfelementsf/fnon-returnfvalvef/fhosefandfpipelinesf/ffunctionfandfleak-tightnessfoff

brakefboosterf/fnon-returnfvalve.fFor further information, see ESI[tronic]

®fffffff®

10. Fluid reservoir

Endfcoverf/ftankf/fsecuringfelementf/fwarningfswitch ®fffffff®11. Brake fluid

Levelf/fappearancef/fbrakeffluidfchangef/fmoisturefcontentf/fboilingfpoint ®fffffff®12. Brake master cylinder

Externalfdamagef/fcorrectfsecuringf/flinefconnectionsf/fleak-tightness ®fffffff®13. ABS/ASR/ESP®/SBC – hydraulic unit

Externalfdamagef/fcorrectfsecuringf/flinefconnectionsf/fcovers,ffunctionf

IMPORTANT: It may be necessary to carry out a hydraulic and electric check for interchanging!

®fffffff®14. Brake pipes, brake hoses

Externalfdamagef/fcorrectfsecuringf/fcorrosionf/finstallation,fnotftwistedf/fage ®fffffff®15. Braking force regulator, braking force limiter

Externalfdamagef/fcorrectfsecuringf/flinefconnectionsf/flinkage,fleverf/ftravelfspringf/ffunction

For further information, see ESI[tronic]

®fffffff®

16. Brake caliper

Externalfdamagef/fcorrectfsecuringf/fbleedfvalvef/fdustfcapsf/fbrakefpadfchannelsf/fguidefelementsf/feasefofff

movementfoffpistonsf/fdustfsealf/fbasicfsetting

®fffffff®17. Disc-brake pad

Brakefpadfthicknessf(*)fdamagef/fcracksf/fshiningf/finstallationfpositionf/fbrakefpadfguidesf/fslidefplatesf

Important: (*) Wear limit at 4 mm pad thickness, measured without pad rear plate

®fffffff®18. Brake disc, brake drum

Wearfdimensionf/fdamagef/fcrackfformationf/fcorrosionf/flateralfrunoutf/fthicknessftolerancef/fradialfrunout ®fffffff®19. Drum brake

Brakefanchorfplatef/fwheelfbrakefcylinderf/fparkingfbrakefleverf/fadjusterf/fbrakefshoesf/fbrakefpadsf/freturnf

springsf/fbasicfsettingf

®fffffff®

20. Brake cables, brake linkage

Externalfdamagef/fsecuringfelementsf/fcorrectfinstallationf/fbreakages ®fffffff®

OK

not

OK

f

Simple All-Round Safety: Tips, Test and Repair Information on Drum Brakes

Tips, Test and Repair Information: Drum Brakes

Preliminary remarks

Theffollowingfdescriptionsfarefintentionallyfgeneralfandf

cannotfapplyftofallfvehiclesfand/orfdrumfbrakefdesigns.

ESI[tronic]fcontainsffurther,fmorefcomprehensivefandf

vehicle-specificfSISfTroubleshootingfInstructionsf

withftroubleshooting,finstallationfpositions,fremoval,f

installationfandfsettingfinstructionsfasfwellfasf

tighteningftorques,ftestfandfsettingfvalues

Important!

· Afterfcompletionfoffthefrepairfwork,ffinalfassemblyftasksf

fffandfchecks,fe.g.fefficiencyftestsfandftestfdrive,fhaveftof

fffbefcarriedfout

1. Preparatory measures

ff Raisefthefvehiclefonftheflift

ff Markfandfdismantlefthefwheels

ff Loosenfthefparkingfbrakefcablesfasffarfasfpossiblefusingfthefadjustmentfunit

2. Disassembly

ff Removefthefplugsffromfthefbrakefanchorfplate

ff Insertingfafsuitablefscrewdriverfthroughfthefopeningf(arrow),fpushfdownfhardfonff

thefparkingfbrakefleverf(parkingfbrakefleverfisfpositionedfatftheffront),fsofthatftheff

stopflugf(yellowfarrow)reachesfthefbrakefshoefandfthefparkingfbrakefleverfandff

brakeffshoesfreachfthefdisassemblyfpositionf

3. Disassembly

ff Iffrequired,floosenfanyftightfbrakefdrumfonfthefwheelfhubfwithfaflightftap

ff Caution:fDofnotfdamagefthefwheelfhub

ff Removefthefbrakefdrum

4. Disassembly

ff Dismantlefthefbrakefshoefholdingfspringfplatefusingfthefspecialftool

ff Removeftheflowerfreturnfspring

ff Detachfthefbrakefshoesfonftheflowerfshoefpinfbushingfandfremoveffromfabove

ff Detachfthefparkingfbrakefcablefonfthefparkingfbrakeflever

Important!

· Forfdrumfbrakesfwithfafparkingfbrakefleverfbehindfthefbrakef

fffshoes,fthefscrewdriverfmustfbefpushedfthroughfafwheelfboltf

fffholeffromfoutside

Tips, Test and Repair Information: Drum Brakes

5. Disassembly

ff Disassemblefthefbrakeftubingfandfbleedfvalve

ff Removefthefwheelfbrakefcylinder

ff Dismantlefthefparkingfbrakefcable

6. Preparing for disassembly

ff Cleanfthefbrakefbrackets,fcheckfforfreusabilityfandf f f f

applyfcorrosionfprotection

ff Cleanfthefwheelfhubfsurfacesfusingfthefspecialfbrush

ff Checkfthefrotationfoffthefwheelfhub

7. Parking brake cable assembly

ff Correctlyfroutefandfsecurefthefnewfparkingfbrakefcableftofthefvehicleffloor

ff Insertfthefparkingfbrakefcablefintofthefholefinfthefbrakefanchorfplatefandfsecure

Important!

· Parkingfbrakefcablesfarefwearingfparts.fWefrecommendfthatfyouf

f replacefthemfwhenfthefdrumfbrakesfarefrepaired.

· Dependingfonfvehicleftype,fthefparkingfbrakefcablesfmustfbefsecuredf

f usingfafretainingfringfaccordingftofDINf6799f(circlip).fAfnewfretainingf

f ringfmustfbefusedfduringfassembly

Important!

· Thefpistonfclipsfpreventfthefpistonffromfinadvertentlyffallingfoutfofff

f thefwheelfbrakefcylinder

· Dependingfonfvehicleftype,fitfmayfbefnecessaryftoffirstffitfthefbrakeff

f shoes,fbeforeffittingfthefwheelfbrakefcylinder

Important!

· Dependingfonfvehicleftype,fthefparkingfbrakefcablesfmayfbefsecuredfffff

fffusingfafretainingfringfaccordingftofDINf6799f(circlip).fThisfmustfbefffff

fffremovedffromfthefbrakefbracketsfbeforefdismantling

Important!

· Dofnotfusefmachineftools

8. Wheel brake cylinder assembly

ff Fitfthefnewfwheelfbrakefcylinderftofthefbrakefanchorfplatefandfsecure

ff Afterfassembly,ffitfthefpistonfclipsfonfthefwheelfbrakefcylinder

9. Brake hose and brake tubing assembly

ff Fitfthefnewfbrakefhosefandfbrakeftubingfinfthefcorrectfposition

ff Usefafnewfretainingfclampfforfthefbrakefhose

Important!

· Thefbrakefhosefandfbrakeftubingfarefsubjectedftofextremefpressuref

f dueftofenvironmentalfinfluences,fwaterfspray,froadfsalt,fstonesfetc.f

f Wefrecommendfthatftheyfarefreplacedfwhenfthefdrumfbrakefisfrepaired

Tips, Test and Repair Information: Drum Brakes

Important!

· Dependingfonfthefvehicleftype,fitfmayfbefnecessaryftoffitfthefbrakeff f

f shoesfbeforeffittingfthefwheelfbrakefcylinder

Order Number

Tube: 5 000 000 150

Brush-cap can: 5 000 000 163

10. Brake shoe assembly

ff Lubricatefallfsupportfpointsfoffthefbrakefshoesfonfthefbrakefanchorfplatefandff

shoefpinfbushingfusingfBoschfSuperfit

11. Assembly of the new brake shoes

ff Fitfthefparkingfbrakefleverftofthefparkingfbrakefcable

ff Removeftheftransportfprotectionffromfthefbrakefshoefsetsf(plasticfpart)

ff Removeftheflowerfreturnfspring

12. Brake shoe assembly

ff Insertfthefbrakefshoefsetfandfthenfplacefonlyfonfthefwheelfbrakefcylinder

ff Fitfthefbrakefshoefwithfthefparkingfbrakeflevelfinftheflowerfshoefpinfbushing

ff Refitfthefreturnfspringfinfthefcorrectfposition

ff Fitfthefotherfbrakefshoefagainstfthefspringfforcefinftheflowerfshoefpinfbushing.f

Pliersfmayfbefrequiredfdependingfonfdesign

13. Brake shoe assembly

ff Fitfthefbrakefshoefwithfthefparkingfbrakeflevelfinftheflowerfshoefpinfbushing

ff Refitfthefreturnfspringfinfthefcorrectfposition

ff Fitfthefotherfbrakefshoefagainstfthefspringfforcefinftheflowerfshoefpinfbushing.f

Pliersfmayfbefrequiredfdependingfonfdesign

ff Removefthefpistonfclipffromfthefwheelfbrakefcylinder

14. Brake shoe assembly

ff Installfthefbrakefshoefholdingfspringfplatefusingfthefspecialftool

ff Placefthefbrakefshoesfroughlyfinfthefcenterfoffthefbrakefanchorfplate

ff Checkfthefcorrectfpositioningfoffallfpartsfandfremovefassemblyftracesff f

fromfthefbrakefshoes