drum brakes j

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DRUM BRAKES

Introduction

CAUTION

Older brake pads or shoes may contain asbestos, which has been determined to

be cancer causing agent. Never clean the brake surface with compressed air!

Avoid inhaling any dust from any brake surface! When cleaning brake surfaces,

use a commercially available brake cleaning fluid.

Cirrus, tratus and ree"e models are e#uipped with a $ shoe

%leading&trailing', internal e(panding type of rear drum brakes with automatic

self)ad*uster mechanisms. +he automatic self)ad*uster mechanisms used on

these vehicles are new designs and function differently than the screw type

ad*usters used in the past. +hese new self)ad*usters are still actuated each

time the vehicles service brakes are applied. +he new ad*usters are located

directly below the wheel cylinders.

+he ebring coupe, convertible and Avenger models are e#uipped with a rear

wheel, $ shoe %leading&trailing' internally e(panding type of drum brakes with

an automatic self)ad*uster mechanism. +he automatic self)ad*uster

mechanism used on these vehicles is the screw type ad*uster. +he self)

ad*uster mechanism is actuated each time the vehicles service brakes areapplied. -enerally, drum brakes with a self)ad*usting mechanism do not

re#uire manual brake shoe ad*ustment. Although, in the event that the brake

shoes are replaced, it is advisable to make the initial ad*ustment manually to

speed up the initial ad*ustment time. +he initial ad*ustment procedure must

be done prior to driving the vehicle.


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rum rake Components

Click to enlarge

Brake Drums

REMOVAL & IS!ALLA!IO

"# Raise and sa$el% suort t'e (e'icle#

)# Remo(e t'e rear tire and *'eel assem+l%#

If the vehicle has high mileage, the brake drums may have a ridge

worn in them by the brake shoes. This ridge causes the brake drum to

interfere with the brake shoes, thereby preventing drum removal.

Clearance can be obtained by backing off the brake's automatic self-

adjuster mechanism, using the following procedures.

acking off the rear brake shoe ad*ustment

Click to enlarge

,# -or Cirrus. Stratus and Bree/e models. use t'e $ollo*ing rocedure0

"# Locate and remo(e t'e ru++er lug $rom t'e

+rake suort late 1+acking late2#

)# Insert a +rake ad3uster tool or similarl%4s'aed

r%tool t'roug' t'e automatic ad3uster access

'ole and engage t'e teet' on t'e ad3uster

*'eel# Rotate t'e ad3uster *'eel so it is mo(ed

to*ard t'e $ront o$ t'e (e'icle# Continue

mo(ing t'e ad3uster until it stos5 t'is *ill +ack

o$$ t'e ad3ustment o$ t'e rear +rake s'oes#

6# -or Se+ring coue. con(erti+le and A(enger models. use t'e $ollo*ing

rocedure $or releasing t'e sel$4ad3usting mec'anism0

"# Locate and remo(e t'e ru++er lug $rom t'e

+rake suort late 1+acking late2#

)# Insert a +rake ad3uster tool or similarl% s'aed

r%tool t'roug' t'e automatic ad3uster access
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'ole and care$ull% us' t'e ad3uster actuating

le(er out o$ engagement *it' t'e ad3uster star

*'eel# 7'ile 'olding t'e le(er a*a% $rom t'e

star *'eel. insert a second r%tool t'roug' t'e

access 'ole and engage t'e teet' on t'e

ad3uster *'eel# Rotate t'e ad3uster *'eel

u*ard a*a% $rom t'e ground5 t'is *ill +ack o$$

t'e ad3ustment o$ t'e rear +rake s'oes#

After removing the rear wheel, pull off the brake drum

8# Remo(e t'e +rake drum $rom t'e 'u+ assem+l%#

To install

9# Insect t'e +rake drum $or cracks or signs o$ o(er'eating# Measure t'e drum

run4out and diameter# I$ not to seci$ication. resur$ace t'e drum# Run4out

s'ould not e:ceed ;#;;9 in# 1;#"8mm2# !'e diameter (ariation 1o(al s'ae2 o$

t'e drum +raking sur$ace must not e:ceed eit'er ;#;;)8 in# 1;#;96mm2 in ,;

degrees o$ rotation. or ;#;;,8 in# 1;#;# Install t'e +rake drum onto t'e 'u+ assem+l%#


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diameter (ariation 1o(al s'ae2 o$ t'e drum

+raking sur$ace must not e:ceed eit'er ;#;;)8

inc' 1;#;96mm2 in ,;@ rotation. or ;#;;,8 inc'

1;#;


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Brake S'oes

IS?EC!IO

"# On Cirrus. Stratus. Se+ring con(erti+le and Bree/e models. measure t'e

com+ined t'ickness o$ t'e +rake s'oe rim and lining# !'e minimum leading

+rake s'oe rim and lining t'ickness seci$ication is"

96inc'

1)#


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rake shoe lining thickness measurement)ebring coupe and Avenger

)# On Se+ring coue and A(enger models. measure t'e t'ickness o$ t'e +rake

s'oe lining material onl%# !'e minimum +rake s'oe lining t'ickness

seci$ication is ,961"#;mm2#

,# I$ an% o$ t'e measurements $all +elo* t'e minimum seci$ications. relace t'e

+rake s'oes#

6# !'oroug'l% clean all arts# !'e +rake lining s'ould s'o* contact across t'e

entire *idt' and $rom 'eel to toe5 ot'er*ise. relace# Clean and insect t'e

+rake suort late and t'e automatic ad3uster mec'anism# Be sure t'at t'e

ad3uster mec'anism 'as $ull mo(ement t'roug'out it ad3ustment range and

t'at its teet' s'ould +e in good condition# I$ t'e ad3uster is *orn or damaged.

relace it# I$ t'e ad3uster is ser(icea+le. lu+ricate t'e mo(ing arts *it' 'ig'4temerature grease# C'eck t'e +rake srings# O(er'eating indications are

aint discoloration or distorted end coils# Relace arts as reuired#

REMOVAL & IS!ALLA!IO

Cirrus. Stratus and Bree/e


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0emove the actuating spring from the ad*uster mechanism and trailing brake shoe

0emove the upper spring using needlenose pliers


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Notice that the hooks on each end of the spring are different, so it can only be installed one way

0emove the lower return spring from the brake shoes


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1nfasten the trailing brake shoe retainer support plate

0emove the retainer and pin attaching the trailing brake shoe assembly to the brake support plate


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0emove the leading brake shoe and ad*uster mechanism as an assembly

0emove the ad*uster mechanism from the brake shoe


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1se pliers to separate the parking brake cable from the actuating lever

1nlike most actuating levers, this actuator is permanently attached to the shoe by a rivet


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Clean the brake shoe contact points of the backing plate ...

... then lubricate the contact points


)# Remo(e t'e rear tire and *'eel assem+lies#

#egardless of their wear pattern, when brake shoes are replaced on

one side of the vehicle, they must also be replaced on the other side.

It is advisable, however, to complete one side before beginning the

other.

,# Remo(e t'e +rake drum $rom t'e 'u+ assem+l%#

6# Remo(e t'e actuating sring $rom t'e ad3uster mec'anism and trailing +rake

s'oe#8# Remo(e t'e uer return sring $rom t'e +rake s'oes#

9# Remo(e t'e lo*er return sring $rom t'e +rake s'oes#


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># Remo(e t'e +rake s'oe retainer and in attac'ing t'e leading +rake s'oe

assem+l% to t'e +rake suort late#


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))# Lo*er t'e (e'icle#

),# Ad3ust t'e rear +rakes s'oes#

)6# Road test t'e (e'icle to c'eck $or roer +rake oeration#

Se+ring Con(erti+le

)hen removing the rear brake shoes, replace the brake shoes from

only one side of the vehicle at a time. This is due to the automatic

adjustment feature of the parking brake system. If the brake shoes

are removed from both sides of the vehicle at the same time, the

automatic adjuster will remove all slack from the parking brake

cables, which will make brake shoe installation e"tremely difficult.


)# Remo(e t'e rear *'eel assem+l%#

,# Remo(e t'e +rake drum $rom t'e 'u+ assem+l%#

Note the location of the automatic ad*usters actuating spring and lever

Click to enlarge
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0emove the brake shoe upper return spring

Click to enlarge

0emove the brake shoe lower return spring

Click to enlarge

6# Remo(e t'e ad3usting le(er actuating sring $rom t'e leading +rake s'oe#

Remo(e t'e automatic ad3uster actuating le(er $rom t'e leading +rake s'oe#

8# !'read t'e ad3uster star *'eel all t'e *a% into t'e ad3uster. *'ic' *ill remo(e

all tension $rom t'e ad3uster#

9# Remo(e t'e uer and lo*er return srings $rom t'e +rake s'oes#
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0emove the leading brake shoe hold)down spring and pin

Click to enlarge

0emove the automatic ad*uster from the trailing brake shoe

Click to enlarge
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0emove the parking brake lever)to)trailing brake shoe retaining clip

Click to enlarge

0emove the trailing brake shoe

Click to enlarge

># Remo(e t'e +rake s'oe 'old4do*n sring and in attac'ing t'e leading +rake

s'oe assem+l% to t'e +rake suort late#


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2ubricate the brake shoe contact areas

Click to enlarge

/nstall the wave washer onto the pin of the parking brake actuating lever

Click to enlarge

",# Lu+ricate t'e 9 +rake s'oe contact oints and t'e +rake s'oe anc'or oints

*it' 'ig'4temerature grease#

"6# Install t'e *a(e *as'er on t'e i(ot in o$ t'e arking +rake actuating le(er#

"8# Install t'e trailing +rake s'oe onto t'e attac'ing in o$ t'e arking +rake

actuating le(er#

"9# ?osition t'e trailing +rake s'oe onto t'e +rake suort late and +e sure t'e

trailing +rake s'oe is suarel% seated on t'e suort late s'oe contact areas

and install t'e +rake s'oe 'old4do*n sring on t'e 'old4do*n in#

"># Install t'e arking +rake actuating le(er4to4trailing +rake s'oe retaining cli#

"


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)"# Install t'e automatic ad3uster actuating le(er and sring onto t'e leading

+rake s'oe#

))# Manuall% ad3ust t'e +rake s'oes to t'e $urt'est ad3usted osition +ut not so

$ar as to inter$ere *it' t'e installation o$ t'e +rake drum#

),# Install t'e +rake drums# C'eck and ad3ust t'e +rake s'oes as necessar%#

)6# Install t'e *'eel and tire# !ig'ten t'e lug nuts in a star attern to =8 $t# l+s#

1")= m2#

)8# Lo*er t'e (e'icle#)9# Road test t'e (e'icle to c'eck $or roer +rake oeration#

Se+ring Coue and A(enger

"# Raise and sa$el% suort t'e (e'icle and remo(e t'e *'eel assem+l%#

)# Remo(e t'e +rake drum#

*ote the location of all springs and clips for proper reassembly.

,# Remo(e t'e s'oe4to4le(er sring and remo(e t'e ad3uster le(er#

6# Remo(e t'e auto ad3uster assem+l%#

8# Remo(e t'e retainer sring#

9# Remo(e t'e 'old4do*n srings. *as'ers and ins#

># Remo(e t'e s'oe4to4s'oe sring#


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+sually, self-adjusting drum brakes do not necessitate manual

adjustment. owever, in the event of a brake reline, you should make

the initial adjustment to speed up the adjustment period.

"# Make sure t'e arking +rake is $ull% released#

)# Raise and sa$el% suort t'e (e'icle so t'at all *'eels are $ree to turn#

,# Remo(e t'e rear +rake ad3usting 'ole ru++er lug $rom t'e rear o$ t'e +rakes'oe suort late#

6# Insert a suita+le +rake ad3usting tool t'roug' t'e ad3usting 'ole in t'e suort

late and against t'e star *'eel o$ t'e ad3usting scre*# Mo(e t'e 'andle o$ t'e

tool do*n*ard until a slig't drag is $elt *'en t'e tire is rotated#

tar wheel type self)ad*uster mechanism components)ebring coupe&convertible and Avenger

Click to enlarge

acking off the rear brake shoe ad*ustment

Click to enlarge

8# Insert a t'in scre*dri(er or eui(alent into t'e ad3usting 'ole# ?us' t'e

ad3usting le(er out o$ engagement *it' t'e star *'eel# Be (er% care$ul not to

+end t'e ad3usting le(er or contort t'e le(er sring# 7'ile 'olding t'e

ad3usting le(er out o$ engagement *it' t'e star *'eel. +ack o$$ t'e star *'eel

to guarantee a $ree *'eel *it' no drag#

9# Reeat t'e ad3ustment rocedure at t'e ot'er rear *'eel# A$ter t'e rocedure

is comlete. install t'e ad3usting 'ole ru++er lugs in t'e rear +rake suort

lates#
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># A$ter ad3ustment. al% and release t'e arking +rake le(er one time#


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1sing a flare nut wrench, loosen the brake line fitting to the wheel cylinder ...

... then unscrew the fitting from behind the wheel cylinder


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After removing the mounting bolts, remove the wheel cylinder from the brake backing plate

8# Disconnect and lug t'e rear +rake $le: 'ose $rom t'e *'eel c%linder#

9# Remo(e t'e ) *'eel c%linder attac'ing +olts#

># Remo(e t'e *'eel c%linder $rom t'e +acking late#

To install

inc' l+s# 1"" m2

o Se+ring con(erti+le4""8 inc' l+s# 1", m2

o Se+ring coue and A(enger4> $t# l+s# 1"; m2

";# and4start t'e +rake line to t'e *'eel c%linder# !ig'ten t'e +rake line $itting as

$ollo*s0

o Cirrus. Stratus. Se+ring con(erti+le and Bree/e4

"68 inc' l+s# 1"> m2

o Se+ring coue and A(enger4"" $t# l+s# 1"8 m2

""# Install t'e rear +rake s'oes# Install t'e +rake drum onto t'e *'eel 'u+#

")# Install t'e tire and *'eel assem+l%# !ig'ten in a star attern to =8 $t# l+s# 1")=

m2#

",# Ad3ust t'e rear +rakes#

"6# Bleed t'e entire +rake '%draulic s%stem#

"8# Road test t'e (e'icle to c'eck $or roer +rake oeration#

OVERAUL

Wheel cylinder overhaul kits may be available, but often at little or no savings

over a reconditioned wheel cylinder. /t often makes sense with these

components to substitute a new or reconditioned part instead of attempting

an overhaul.

/f no replacement is available, or you would prefer to overhaul your wheel

cylinders, the following procedure may be used. When rebuilding and

installing wheel cylinders, avoid getting any contaminants into the system.


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Always use clean, new, high #uality brake fluid. /f dirty or improper fluid has

been used, it will be necessary to drain the entire system, flush the system

with proper brake fluid, replace all rubber components, then refill and bleed

the system.

"# Remo(e t'e *'eel c%linder $rom t'e (e'icle and lace on a clean *ork+enc'#

)# -irst remo(e and discard t'e old ru++er +oots. t'en *it'dra* t'e istons#?iston c%linders are euied *it' seals and a sring assem+l%. all located

+e'ind t'e istons in t'e c%linder +ore#

0emove the outer boots from the wheel cylinder,# Remo(e t'e remaining inner comonents. seals and sring assem+l%#

Comressed air ma% +e use$ul in remo(ing t'ese comonents# I$ no

comressed air is a(aila+le. +e VERF care$ul not to score t'e *'eel c%linder

+ore *'en remo(ing arts $rom it# Discard all comonents $or *'ic'

relacements *ere sulied in t'e re+uild kit#


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Compressed air can be used to remove the pistons and seals

0emove the pistons, cup seals and spring from the cylinder

6# 7as' t'e c%linder and metal arts in denatured alco'ol or clean +rake $luid#

1se brake fluid and a soft brush to clean the pistons ...


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... and the bore of the wheel cylinder

WARNING

Never use a mineral)based solvent such as gasoline, kerosene or paint thinner

for cleaning purposes. +hese solvents will swell rubber components and #uickly

deteriorate them.

8# Allo* t'e arts to air dr% or use comressed air# Do not use rags $or cleaning.

since lint *ill remain in t'e c%linder +ore#

9# Insect t'e iston and relace it i$ it s'o*s scratc'es#

Once cleaned and inspected, the wheel cylinder is ready for assembly

># Lu+ricate t'e c%linder +ore and seals using clean +rake $luid#


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2ubricate the cup seals with brake fluid

/nstall the spring, then the cup seals in the bore


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2ightly lubricate the pistons, then install them

";# Insert t'e ne* +oots into t'e counter+ores +% 'and# Do not lu+ricate t'e

+oots#

+he boots can now be installed over the wheel cylinder ends

""# Install t'e *'eel c%linder#

Chilton Automotive Information Systems. 2004 Thomson Delmar Learning.

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