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