chrysler dakota part4

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BRAKES

CONTENTS

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ABS BRAKE OPERATION AND SERVICE . . . . . . 51ANTILOCKBRAKE SYSTEM DIAGNOSIS . . . . . . 8DISC BRAKE ROTOR SERVICE . . . . . . . . . . . . . 41DISC BRAKES2-WHEEL DRIVE . . . . . . . . . . . 27DISC BRAKES4-WHEEL DRIVE . . . . . . . . . . . 34DRUM BRAKES . . . . . . . . . . . . . . . . . . . . . . . . . 20GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1MASTER CYLINDERBRAKE FLUID

BRAKELINES . . . . . . . . . . . . . . . . . . . . . . . . . . 12

PARKINGBRAKES . . . . . . . . . . . . . . . . . . . . . . . 63POWER BRAKE BOOSTERBRAKE PEDAL

STOPLAMP SWITCH . . . . . . . . . . . . . . . . . . . 17RWAL BRAKE OPERATION AND SERVICE . . . . 44SERVICE BRAKE DIAGNOSIS . . . . . . . . . . . . . . . 3SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . 68

GENERAL INFORMATION

INDEX

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Antilock Brake Systems . . . . . . . . . . . . . . . . . . . . . 1Brake Fluid/Lubricants/Cleaning Solvents . . . . . . . . . 1Brake Safety Precautions . . . . . . . . . . . . . . . . . . . . 2

Brake Warning Lights . . . . . . . . . . . . . . . . . . . . . . . 1Hydraulic and Vacuum Components . . . . . . . . . . . . 1Wheel Brake Units . . . . . . . . . . . . . . . . . . . . . . . . . 1

WHEEL BRAKE UNITSAN models are equipped with power assist front

disc and rear drum brakes. The front brake units

consist of single piston calipers and vented disc brake

rotors. The rear drum brakes are dual shoe, servo

style units with automatic adjuster mechanism and

cable operated parking brakes.

HYDRAULIC AND VACUUM COMPONENTSAll models are equipped with a vacuum operated

power brake booster, a dual reservoir master cylinder

and a combination valve. The valve consists of a

front brake metering (hold-off) valve and a front/rear

brake pressure differential valve and switch.

ANTILOCKBRAKE SYSTEMSTwo antilock brake systems are available on AN

models. A rear wheel antilock brake system (RWAL )is standard. An all-wheel antilock brake system(ABS) is available as an option.

The RWAL and ABS systems are designed to retardwheel lockup during periods of high wheel slip whenbraking. Retarding wheel lockup is accomplished bymodulating fluid pressure to the wheel brake units.Refer to the antilock brake sections for operation andservice information.

BRAKE WARNING LIGHTSA red warning light is used to alert the driver if a

pressure differential exists between the front and

rear hydraulic systems. The light also alerts the

driver when the parking brakes are not released. The

light i s l ocated at the left side of the instrument clus-

ter.

An amber warning light is used for the antilock

brake system. It is adjacent to the red indicator light

in the instrument cluster. T he amber light alerts the

driver if an antilock system fault occurs.

BRAKE FLUID/LUBRICANTS/CLEANING SOLVENTSRecommended flui d for AN models is Mopar brake

fluid or equivalent meeting SAE J 1703 and DOT 3standards.

When servicing rear brakes, use Mopar multi mile-

age grease to lubricate caliper slide surfaces, drum

brake pivot pins and shoe contact points on the back-

ing plates. Use GE 661 or Dow 111 sili cone grease on

caliper bushings and mounting pins.

Use fresh brake fluid or Mopar brake cleaner to

clean or flush brake system components. These are

the only cleaning materials recommended.

BRAKES 5 - 1


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CAUTION: Never use gasoline, kerosene, alcohol,

motor oil, transmission fluid, or any fluid containingmineral oil to clean the system components. Thesefluids damage rubber cups and seals. If systemcontamination is suspected, check the fluid for dirt,discoloration, or separation into distinct layers.

Drain and flush the system with new brake fluid if

contamination is suspected.

BRAKE SAFETYPRECAUTIONS

WARNING: SOME AFTERMARKET BRAKELININGMAY CONTAIN ASBESTOS FIBERS. THIS SHOULDBE TAKEN INTO ACCOUNT WHEN SERVICING AVEHICLE HAVING PRIOR BRAKE SERVICE. WEAR

A RESPIRATOR WHEN CLEANING BRAKE PARTSBECAUSE ASBESTOS FIBERS CAN BE A HEALTH

HAZARD. NEVER CLEAN BRAKE COMPONENTS

WITH COMPRESSED AIR OR BY DRY BRUSHING.

USE A VACUUM CLEANER SPECIFICALLY DE-

SIGNED TO REMOVE ASBESTOS FIBERS. IF A

SUITABLE VACUUM CLEANER IS NOT AVAILABLE,

PERFORM CLEANING OPERATIONS WITH A WATER

DAMPENED CLOTH. DO NOT CREATE DUST BY

SANDING, OR GRINDING BRAKELINING. DISPOSEOF ALL DUST AND DIRT SUSPECTED OF CONTAIN-

ING ASBESTOS FIBERS IN SEALED BAGS OR

CONTAINERS. FOLLOW ALL RECOMMENDED

PRACTICES PRESCRIBED BY THE OCCUPATIONAL

SAFETY AND HEALTH ADMINISTRATION (OSHA)

AND THE ENVIRONMENTAL PROTECTION AGENCY

(EPA) FOR HANDLING, PROCESSING, AND DISPO-

SITION OF MATERIAL THAT MAY CONTAIN ASBES-

TOS FIBERS.

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SERVICE BRAKE DIAGNOSIS

INDEX

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Combination Valve Testing . . . . . . . . . . . . . . . . . . . 6Component Inspection . . . . . . . . . . . . . . . . . . . . . . 4Diagnosing Parking Brake Problems . . . . . . . . . . . . 6Diagnosing Service Brake Problems . . . . . . . . . . . . 4Diagnosis Procedures . . . . . . . . . . . . . . . . . . . . . . . 3Master Cylinder/Power Booster Test . . . . . . . . . . . . 6

Power Booster Check Valve Test . . . . . . . . . . . . . . . 7Power Booster Vacuum Test . . . . . . . . . . . . . . . . . . 7Preliminary Brake Check . . . . . . . . . . . . . . . . . . . . . 3Road Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Service Brake Warning Light Illumination . . . . . . . . . 3

DIAGNOSIS PROCEDURESThe diagnosis information in this section covers

service brake components only. Antilock brake compo-nent diagnosis is covered in the antilock brake diag-nosis section.

Service brake components include front/rear brake-shoes, disc brake calipers, wheel cylinders, brake

drums, support plates, brakeli nes, master cylinder,power brake booster, and parking brake components.

Brake diagnosis involves determining if the prob-lem is related to a mechanical, hydraulic, vacuum, orelectrically operated component. A preliminary check,road testing and component inspection can all beused to determine a problem cause.

Road testing will either verify proper brake opera-tion or confirm the existence of a problem. Compo-nent inspection will then identify the actual causalpart.

SERVICEBRAKE WARNINGLIGHT ILLUMINATIONThe first diagnosis step is observation of the warn-

ing li ght. I llumination of the red light indicates a hy-draulic problem in either the front or rear brakesystem. I t may also i ndicate that the parking brakesare still applied.

An amber warning light indicates a problem in theantilock system. Refer to the antilock brake diagnosissection.

I f neither warning light is i lluminated, the problemwill be related to a mechanical, hydraulic, or vacuumcomponent such as a brakeshoe, rotor, caliper, mastercyli nder, or brake booster.

PRELIMINARYBRAKE CHECKThe next step in brake diagnosis should be a pre-

liminary check. This involves inspecting fluid level,parki ng brake action, wheel and tire condition, leakchecking and testing brake pedal response.

Preliminary Brake Check Procedure

(1) I f amber antilock light is illuminated, refer toAntilock Brake System Diagnosis. However, if redwarning l ight is illuminated, or if neither warningli ght is il luminated, continue check procedure.

(2) I nspect condition of tir es and wheels. Damaged

wheels and worn, damaged, or underinflated tires

can cause pull, shudder, tramp, and a condition sim-

ilar to grab.

(3) I f complaint was based on noise when braking,

check suspension components. J ounce front and rear

of vehicle and listen for noise that might be caused

by loose, worn or damaged suspension or steeringcomponents.

(4) I nspect brake fluid level and condition. Note

that fluid level in disc brake reservoir section will de-

crease in proportion to lining wear. This is a normal

condition.

(a) I f fluid level is abnormally low, look for evi-

dence of leaks at calipers, wheel cylinders, brake-

lines and master cylinder.

(b) I f fluid appears contaminated, drain out a

sample. I f fluid is separated into layers, or obvi-

ously contains oil or a substance other than brake

fluid, the system seals and cups will have to be re-placed and the hydraulic system flushed.

(5) Check parking brake operation. Verify free

movement and ful l release of cables and foot pedal or

hand lever. Also note if vehicle was being operated

with parking brake partially applied.

(6) Check brake pedal operation. Pedal should

have adequate free play and not bind at any point of

travel. I f pedal lacks free play, check pedal andpower booster for being loose or for bind condition.Do not road test until condition is corrected.

(7) I f components checked appear OK , and brake

action is sufficient to stop vehicle, proceed to roadtest. However, if brake action is impaired, do notroad test vehicle. I nstead, raise vehicle on hoist anddisassemble/repair as needed.

ROAD TESTINGA road test will confirm or deny the existence of a

problem. The final diagnosis procedure involves roadtest analysis and a visual inspection of brake compo-nents.

(1) I f complaint involved low brake pedal, makeseveral low speed stops and note if pedal returns to

SERVICE BRAKE DIAGNOSIS 5 - 3


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normal height. If pedal drops off, or brake action

is impaired, immediately return to shop and be-

gin repair.

(2) Check brake pedal response with transmission

in Neutral and engine running. Pedal should remain

firm under steady foot pressure.(3) During road test, make normal and firm brake

stops in 20-35 mph range. Note faulty brake opera-tion such as pull, grab, drag, noise, low pedal, hardpedal, fade, pedal pulsation, etc.

(4) I nspect brake components and refer to problemdiagnosis information for causes of various brakeconditions.

COMPONENT INSPECTIONFl uid leak points and dragging brake units can

usually be located without removing any components.The area around a leak point will be wet with fluid.The components at a dragging brake unit (wheel,tire, rotor) will be quite warm or hot to the touch.

Other brake problem conditions will require compo-nent removal for proper inspection. Raise the vehicleand remove the necessary wheel brake componentsfor better visual access.

During component inspection, pay parti cular atten-tion to heavily rusted/corroded brake components(e.g. rotors, caliper pistons, brake r eturn/holddownsprings, support plates, etc.).

Heavy accumulations of rust may be an indicator ofrust and corrosion damage to a brake component. I tis wise to remove surface rust in order to accuratelydetermine the depth of rust penetration and damage.L ight surface rust is fairly normal and not a major

concern (as l ong as it is removed). However, heavyrust buildup, especially on high mileage vehicles,may actually cover structural damage to such impor-tant components as: brakelines; rotors; supportplates; and brake booster.

DIAGNOSING SERVICE BRAKE PROBLEMS

PEDAL FALLS AWAY

A brake pedal that falls away under steady footpressure is generally the result of a system leak. Theleak point could be at a brakeline, fitting, hose, orcaliper. I nternal leakage in the master cylindercaused by worn or damaged piston cups, may also bethe problem cause.

I f leakage is severe, fluid will be evident at oraround the leaking component. However internalleakage in the master cylinder will not be physicallyevident. Refer to the cylinder test procedure in thissection.

LOW PEDAL

I f a low pedal is experienced, pump the pedal sev-eral times. I f the pedal comes back up, worn liningand worn rotors or drums are the likely causes.

A decrease in fluid level in the master cylinder res-

ervoirs may only be the result of normal lining wear.

Fluid level will decrease in proportion to wear. I t is a

result of the outward movement of caliper and wheel

cylinder pistons to compensate for normal wear. Top

off the reservoir flui d level and check brake operation

to verify proper operation.

SPONGY PEDAL

A spongy pedal is most often caused by air in the

system. Thin brake drums or substandard brake

lines and hoses can also cause a spongy pedal. The

proper course of action is to bleed the system and re-

place thin drums and suspect quality brake lines and

hoses.

HARD PEDAL OR HIGH PEDAL EFFORT

A hard pedal or high pedal effort may be due to lin-

ing that is water soaked, contaminated, glazed, or

badly worn. The power booster or check valve could

also be faulty. Test the booster and valve as describedin this section.

BRAKE DRAG

Brake drag occurs when the lining is in constant

contact with the rotor or drum. Drag can occur at one

wheel, all wheels, fronts only, or rears only. I t is a

product of incomplete brakeshoe release. Drag can be

minor or severe enough to overheat the linings, ro-

tors and drums.

Brake drag also has a direct effect on fuel economy.

I f undetected, minor brake drag can be misdiagnosed

as an engine or transmission/torque converter prob-lem.

Minor drag wil l usually cause slight surface char-

ring of the lining. It can also generate hard spots in

rotors and drums from the overheat-cool down pro-

cess. I n most cases, the rotors, drums, wheels and

tires are quite warm to the touch after the vehicle is

stopped.

Severe drag can char the brake lining all the way

through. I t can also distort and score rotors and

drums to the point of replacement. The wheels, tir es

and brake components will be extremely hot. I n se-

vere cases, the lining may generate smoke as it charsfrom overheating.

Some common causes of brake drag are:

seized or improperly adjusted parking brake cables

loose or damaged wheel bearing

seized cali per or wheel cylinder piston

caliper binding on corroded bushings or rusted

slide surfaces

loose caliper mounti ng bracket

drum brakeshoes binding on worn-damaged sup-

port plates

misassembled components

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I f brake drag occurs at all wheels, the problem may

be related to a blocked master cylinder return port or

faulty power booster (binds-does not release).

An improperly installed or adjusted stoplamp

switch can also cause brake drag. I f the switch is po-

sitioned so it prevents full pedal return, a partial ap-

ply and drag will occur.

BRAKE FADE

Brake fade is a product of overheating caused by

brake drag. Brake overheat and fade can also be

caused by riding the brake pedal, making repeated

high deceleration stops in a short time span, or con-

stant braking on steep mountain roads. Refer to the

Brake Drag information in this section for causes.

PEDAL PULSATION

Pedal pulsation is caused by components that are

loose, or beyond tolerance limits.

Disc brake rotors with excessive lateral runout or

thickness variation, or out of round brake drums arethe primary causes of pulsation. Other causes are

loose wheel bearings or calipers and worn, damaged

tires.

PULL

A front pull condition could be the result of contam-

inated lining in one caliper, seized caliper piston,

binding caliper, loose cali per, loose or corroded slide

pins, improper brakeshoes, or a damaged rotor.

A worn, damaged wheel bearing or suspension com-

ponent are further causes of pull. A damaged front

tire (bruised, ply separation) can also cause pull.A common and frequently misdiagnosed pull condi-

tion is where direction of pull changes after a few

stops. The cause is a combination of brake drag fol-

lowed by fade at one of the brake units.

As the dragging brake overheats, efficiency is so re-

duced that fade occurs. Since the opposite brake unit

is still functioning normally, its braking effect is

magnified. This causes pull to switch direction in fa-

vor of the normally functioning brake unit.

When diagnosing a change in pull condition, re-

member that pull wil l return to the original direction

if the dragging brake unit is allowed to cool down(and is not seri ously damaged).

REAR BRAKE GRAB OR PULL

Rear grab or pull is usually caused by an improp-

erly adjusted or seized parki ng brake cable, contam-

inated lining, bent or binding shoes and support

plates, or improperly assembled components. This is

particularly true when only one rear wheel is in-

volved. However, when both rear wheels are affected,

the master cylinder or proportioning valve could be

at fault.

BRAKES DO NOT HOLD AFTER DRIVING

THROUGH DEEP WATER PUDDLES

This condition is generally caused by water soaked

lining. I f the lining is only wet, it can be dried by

driving with the brakes lightly applied for a mile or

two. However, if the lining is both wet and dirty, dis-

assembly and cleaning will be necessary.

BRAKE NOISE

Squeak/Squeal

Brake squeak or squeal may be due to linings that

are wet or contaminated with brake fluid, grease, or

oil. Glazed linings and rotors with hard spots can

also contribute to squeak. Dirt and foreign material

embedded in the brake lining can also cause squeak/

squeal.

A very loud squeak or squeal is frequently a sign of

severely worn brake li ning. I f the li ning has worn

through to the brakeshoes in spots, metal-to-metal

contact occurs. I f the condition i s allowed to continue,

rotors can become so scored that replacement is nec-

essary.

Thump/Clunk

Thumping or clunk noises during braking are fre-

quently not caused by brake components. I n many

cases, such noises are caused by loose or damaged

steering, suspension, or engine components. However,

calipers that bind on the slide pins can generate a

thump or clunk noise. I n addition, worn out, improp-

erly adjusted, or improperly assembled rear brake-

shoes can also produce noise a thump noise.

Chatter/Shudder

Brake chatter, or shudder is usually caused by

loose or worn components, or glazed/burned li ning.

Rotors with hard spots can also contribute to chatter.

Additional causes of chatter are out-of-tolerance ro-

tors, brake lining not securely attached to the shoes,

loose wheel bearings and contaminated brake lining.

BRAKELINING CONTAMINATION

Brakelining contamination is usually a product ofleaking calipers or wheel cylinders, driving throughdeep water puddles, or lining that has become cov-ered with grease and grit during repair.

WHEEL AND TIRE PROBLEMS

Some conditions attributed to brake componentsmay actually be caused by a wheel or tire problem.

A damaged wheel can cause shudder, vibrati on andpull. A worn or damaged tire can also cause vibrationor pull.

Severely worn tires with very little tread left canproduce a grab-like condition as the tires lose and re-cover traction.



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Flat-spotted tires can cause vibration and wheeltramp and generate shudder during brake operation.

A ti re with internal damage such as a severe bruiseor ply separation can cause pull and vibration.

DIAGNOSING PARKING BRAKE PROBLEMS

Adjustment Mechanism

Parking brake adjustment is controlled by acable tensioner. The cable tensioner, once ad-justed at the factory, will not need further ad-justment under normal circumstances. Thereare only two instances when adjustment is re-quired. The first is when a new tensioner, or ca-bles have been installed. And the second, iswhen the tensioner and cables are discon-nected for access to other brake components.

Parking Brake problemCauses

I n most cases, the actual cause of an improperly

functioning parki ng brake (too loose/too tight/wonthold), can be traced to a drum brake component.

The leading cause of improper parking brakeoperation, is excessive clearance between thebrakeshoes and the drum surface. Excessiveclearance is a result of: lining and/or drumwear, oversize drums, or inoperative shoe ad-juster components.

Excessive parking brake lever travel (sometimesdescribed as a loose lever or too loose condition), isthe result of worn brakeshoes/drums, improperbrakeshoe adjustment, or misassembled brake parts.

A too loose condition can also be caused by inop-

erative brakeshoe adjusters. I f the adjusters are mis-assembled, they will not function. In addition, sincethe adjuster mechanism only works during reversestops, it is important that complete stops be made.The adjuster mechanism does not operate when roll-ing stops are made in reverse. The vehicle must bebrought to a complete halt before the adjuster leverwill turn the adjuster screw.

A condition where the parking brakes do not hold,will most probably be due to a wheel brake compo-nent.

I tems to l ook for when diagnosing a parking brakeproblem, are: rear brakeshoe wear rear brake drum wear drums machined beyond allowable diameter (over-size) parking brake front cable not secured to pedal parking brake rear cable seized parking brake strut reversed parking brake strut not seated i n both shoes parking brake lever not seated in secondary shoe parking brake lever or brakeshoe bind on supportplate brakeshoes reversed

adjuster screws seized

adjuster screws reversed

holddown or return springs misassembled or lack

tension

wheel cylinder pistons seized

Brake drums that are machined oversize are diffi-cult to i dentify. I f oversize drums are suspected, the

diameter of the braking surface will have to bechecked with an accurate drum gauge. Oversizedrums will cause low brake pedal and lack of parkingbrake holding ability.

I mproper parki ng brake strut and lever installationwill result in unsatisfactory parki ng brake operation.Intermixing the adjuster screws will cause drag, bindand pull along with poor parking brake operation.

Parki ng brake adjustment and parts replacementprocedures are described in the Parki ng Brake sec-tion.

COMBINATIONVALVETESTING

TESTING METERING VALVE

Metering valve operation can be checked visuallyand with the aid of a helper. Observe the meteringvalve stem while a helper applies and releases thebrakes. If the valve is operating correctly, the stemwill extend slightly when the brakes are applied andretract when the brakes are released. I f the valve isfaulty, replace the entire combination valve as an as-sembly.

TESTING PRESSURE DIFFERENTIAL SWITCH

(1) Have helper sit in drivers seat to apply brake

pedal and observe red brake warning li ght.(2) Raise vehicle on hoist.(3) Connect bleed hose to a rear wheel cylinder

and immerse hose end in container partially filledwith brake fluid.

(4) Have helper press and hold brake pedal to floorand observe warning light.

(a) I f warning light illuminates, switch is operat-ing correctly.

(b) I f light fails to il luminate, check circuit fuse,bulb and wiring. Repair as necessary and repeattest steps (3) and (4).(5) I f warning light still fails to il luminate, check

brakelight and parking brake switches and wiringwith test lamp. Repair or replace parts as necessaryand test differential pressure switch operation again.

(6) I f warning light still does not illuminate, switchis faulty. Replace combination valve assembly, bleedbrake system and verify proper switch and valve op-eration.

MASTER CYLINDER/POWER BOOSTER TEST(1) Start engine and check booster vacuum hose

connections. Hissing noise indicates vacuum leak.Correct any vacuum leak before proceeding.

5 - 6 SERVICE BRAKE DIAGNOSIS


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(2) Stop engine and shift transmission into Neu-

tral.

(3) Pump brake pedal until all vacuum reserve in

booster is depleted.

(4) Press and hold brake pedal under light foot

pressure.

(a) I f pedal holds firm, proceed to step (5).

(b) I f pedal does not hold firm and falls away,master cylinder is faulty (internal leakage).

(5) Start engine and note pedal action.

(a) I f pedal falls away slightly under light foot

pressure then holds fir m, proceed to step (6).

(b) If no pedal action is discernible, power

booster or vacuum check valve is faulty. I nstall

known good check valve and repeat steps (2)

through (5).

(6) Rebuild booster vacuum reserve as follows: Re-

lease brake pedal. I ncrease engine speed to 1500

rpm, close the throttle and immediately turn off igni-

tion.(7) Wait a minimum of 90 seconds and try brake

action again. Booster should provide two or more vac-

uum assisted pedal applications. I f vacuum assist isnot provided, perform booster and check valve vac-uum tests.

POWER BOOSTER CHECKVALVE TEST(1) Disconnect vacuum hose from check valve.(2) Remove check valve and valve seal from

booster (Fig. 1).(3) Hand operated vacuum pump can be used for

test (Fig. 2).

(4) Apply 50.5-67.3 kPa (15-20 inches vacuum) atlarge end of check valve (Fig. 1).

(5) Vacuum should hold steady. I f gauge on pumpindicates any vacuum loss, valve is faulty and mustbe replaced.

POWER BOOSTER VACUUM TEST(1) Connect a vacuum gauge to the booster check

valve with a short length of hose and a T-fitting (Fi g.3).

(2) Start and run engine at idle speed for 60 sec-onds.

(3) Clamp hose shut between vacuum source and

check valve (Fig. 3).(4) Stop engine and observe vacuum gauge.(5) I f vacuum drops more than 1 inch vacuum

(3.368 kPa) in 15 seconds, the booster diaphragm orthe check valve is faulty.

Fig. 1 Typical Vacuum Check Valve And Seal

Fig. 2 Typical Hand Operated Vacuum Pump

Fig. 3 Typical Booster Vacuum Test Connections



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ANTILOCK BRAKE SYSTEM DIAGNOSIS

INDEX

page page

ABS Diagnostic Connector Location . . . . . . . . . . . . 8ABS System Normal and Fault Conditions . . . . . . . . 9ABS/RWAL Control Module Diagnosis . . . . . . . . . . . 9ABS/RWAL Fault Condition Causes . . . . . . . . . . . . 10ABS/RWAL Warning Light Display . . . . . . . . . . . . . . 9Antilock Valve Service and Diagnosis . . . . . . . . . . . 9Clearing RWAL Fault Codes . . . . . . . . . . . . . . . . . 10

Combination Valve Testing . . . . . . . . . . . . . . . . . . 10Diagnosis Procedures . . . . . . . . . . . . . . . . . . . . . . . 8Generating RWAL Flash Codes . . . . . . . . . . . . . . . 10RWAL Diagnostic Connector Location . . . . . . . . . . . 8RWAL Diagnostic Fault Flash Codes . . . . . . . . . . . . 9RWAL Fault Code Capacity . . . . . . . . . . . . . . . . . . 10RWAL Fault Code Identification . . . . . . . . . . . . . . . 10

DIAGNOSIS PROCEDURES

ABS System

Antilock diagnosis involves checking only thosecomponents that form the antilock system. Diagnosisinvolves three basic steps which are: observation of the warning light display visual examination for low fluid, leaks, or dam-aged wires circuit check with DRB scan tool

Visual examination includes a check of reservoirflui d level and condition of the system components.This includes inspection of the sensor wires and elec-tri cal connections. T hings to look for are leaks, looseconnections, or obvious component damage.

Circuit checking involves using the DRB scan toolto identify a faulty circuit or component.

RWAL System

An RWAL system malfunction will be indicated byillumination of the amber warning lamp.

I f a problem occurs, system diagnosis should beginwith a fluid level check followed by a visual exami-nation of the system electri cal and hydrauli c connec-tions. I f obvious defects (low fluid, leaks, looseconnections, etc.) are not evident, road test the vehi-cle. A road test should help determine if a malfunc-tion is actually related to an antilock component.

During the r oad test, note if other conditions areevident such as a low pedal, pull, grab, or similarcondition. Remember that brake malfunctions such

as low fluid, system leaks, or parking brakes par-tially applied will affect antilock system operation.The idea is to determine if a malfunction is actuallyrelated to an antil ock component.

I f a visual inspection and road test do not indicatethe problem cause, check the system fault flashcodes. Refer to the system fault code information inthis section.

ABS DIAGNOSTIC CONNECTOR LOCATIONThe ABS diagnostic connector is located under the

instrument panel near the steering column. The con-

nector is a 4 or 6-way style and is either black, or

light blue in color.

The connector is the ABS access point for the DRBscan tool. System circuits can be tested after the scan

tool is attached.

RWAL DIAGNOSTIC CONNECTOR LOCATIONThe RWAL diagnostic connector is also the service

data link connector (Fig. 1). I t is a black, 2-way con-

nector attached to the single 18 ga. black with white

tracer wire, from terminal 12 on the control module.

The data link wires are plugged into this connector.

The connector is positioned on the passenger side

cowl panel. The module is located under the passen-

ger side of the instrument panel, or on the passenger

side kick panel.

Fig. 1 RWAL Diagnostic (Data Link) ConnectorLocation

5 - 8 ANTILOCK BRAKE SYSTEM DIAGNOSIS


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ABS SYSTEM NORMAL AND FAULT CONDITIONS

Wheel/Tire Size And Input Signals

Antilock system operation depends on accurate sig-

nals from the wheel speed sensors. I deally, the vehi-

cle wheels and ti res should all be the same size and

type to ensure accurate signals and satisfactory oper-

ation.

Operating Sound Levels

On the all wheel ABS system, the pump/motor and

antilock valve solenoids may produce some sound as

they cycle. This is a normal condition and should

not be mistaken for faulty operation. Under most

conditions, pump and solenoid valve operating

sounds will not be audible.

Vehicle Response In Antilock Mode

During antilock braking, the front/rear solenoid

valves cycle rapidly in response to antilock controlmodule inputs.

The driver may experience a slight pulsing sensa-

tion in the brake pedal and vehicle as the solenoid

valves modulate fluid pressure as needed. This is a

normal condition.

Steering Response

A modest amount of steering input is required dur-

ing extremely high deceleration braking, or when

braking on differing traction surfaces. An example of

differing traction surfaces would be when the left

side wheels are on ice and the right side wheels are

on relatively dry pavement.

Loss Of Sensor Input

Wheel speed sensor malfunctions will most likely

be due to loose connections, damaged sensor wires, or

incorrect sensor air gap. An additional fault would be

a result of sensor and tone ring misalignment or

physical damage. A faulty sensor (open, shorted) can

be located with the flash codes or the DRB scan tool

on all wheel antilock models.

ABS/RWAL WARNINGLIGHT DISPLAY

Light Illuminates At Startup

The amber antilock light illuminates at startup as

part of the system self check feature. The light illu-

minates for 2-3 seconds then goes off as part of the

normal self check routine.

Light Remains On After Startup

An system fault is indicated when the l ight re-

mains on after startup. Diagnosis with the flash

codes or DRB scan tool will be necessary to deter-

mine the faulty component.

Light Illuminates During Brake Stop

A system fault such as loss of speed sensor signal

or solenoid failure, will cause the amber warning

light to illuminate. The most effective procedure here

is to check for obvious damage first. Then check the

electronic components with the DRB scan tool, or

flash codes.

ABS/RWAL CONTROL MODULE DIAGNOSISThe electronic module controls all phases of an-

tilock system operation. The module also differenti-

ates between normal and anti lock mode braking.

The module monitors and processes signals gener-

ated by the system sensors at all times.

The module operating program includes a self

check routine that tests each of the system compo-

nents. A failure of the self check program wil l cause

ill umination of the amber warning light. The light

will also illuminate if a solenoid or other system com-

ponent fails during the dynamic phase of initializa-tion.

I f a system malfunction should occur, do not imme-

diately replace the control module. A blown system

fuse, bad ground, or loss of feed voltage will cause

system faults similar to a module failure. Never re-

place the module unless flash code, or scan tool

diagnosis indicates replacement is actually nec-

essary.

ANTILOCKVALVE SERVICEAND DIAGNOSISThe front and rear antilock valves are serviced only

as assemblies. However, neither valve should be re-

placed unless a fault has been confir med.

On the rear wheel antilock system, verify fault con-

ditions with the diagnostic flash codes.

On models with the all wheel ABS system, use the

DRB scan tool to verify a fault condition.

RWAL DIAGNOSTIC FAULT FLASHCODESThe microprocessor in the electronic control module

has a self test feature. This feature is activated

whenever the ignition switch is in the On and Run

positions.

I f a system fault is detected, the control module il -

luminates the antilock light and stores the fault codein the microprocessor memory. I f a fault code is gen-

erated, the module will retain the code after turning

the ignition switch to Off position.

System faults are i dentified by a series of flash

codes that operate through the antilock warning

light. Temporarily grounding the antilock diagnostic

connector will produce the flash code sequence. Refer

to Fault Code Identification in this section.

ANTILOCK BRAKE SYSTEM DIAGNOSIS 5 - 9


10/68

RWAL FAULT CODE CAPACITYThe microprocessor memory will store and display

only one fault code at a time. The stored code can be

displayed by grounding the antilock diagnostic con-

nector.

GENERATINGRWAL FLASHCODES

To generate flash codes, first disconnect the datalink wires from the diagnostic connector. Then mo-

mentarily ground the connector with a jumper wire

and immediately observe the flash code display.

Flash codes are displayed at the antilock warning

light.

RWAL FAULT CODE IDENTIFICATIONTo determine a fault code, momentarily ground the

diagnostic connector and count the number of times

the antilock indicator lamp flashes. Fault codes and

typical malfunctions are outlined in Figure 2.

The initial flash will be a long flash followed by anumber of short flashes. The long flash indicates thebeginning of the fault number sequence and theshort flashes are a continuation of that sequence.You must count the long flash along with theshort flashes for an accurate fault code count.

CLEARINGRWAL FAULT CODESTo clear a fault code, disconnect the control module

connector or disconnect the battery for a minimum offive seconds. During system retest, wait 30 secondsto be sure the fault code does not reappear.

ABS/RWAL FAULT CONDITION CAUSESAntilock system faults can be generated by a cir-

cuit, or component malfunction, or even by thedriver.

Circuit, or component malfunctions will most fre-quently be related to wire harness problems. L ook forloose connections, corroded terminals, damagedwires, or loss of continuity due to connectors filledwith water or dirt. Blown circuit fuses and poorground connections are also common causes for sys-tem faults. A misadjusted, or faulty stop l amp switchwill also cause a system fault.

Wheel speed sensor and control module failures, al-

though infrequent, will be indicated by testing withflash codes, or the DRB scan tool. The faulty partshould not be replaced until diagnosis indicates thisis necessary.

The driver can induce system faults by riding thebrake pedal, pumping the brake pedal, or leaving theparki ng brakes partially applied. These conditionswill cause the antilock warning light to illuminate,despite the fact that a fault has not actually oc-curred.

Another driver induced RWAL fault involves hold-ing the brake pedal in an applied position while

starting the engine. This practice causes thestoplamp switch to be in a closed position when the

engine is started. With the switch closed, the RWAL

system self check feature will not be completed. The

result is illumination of both warning lights and

trouble code 11 registered in system memory.

COMBINATIONVALVETESTING

TESTING METERING VALVE

Metering valve operation can be checked visually

and with the aid of a helper. Observe the metering

Fig. 2 RWAL Flash Codes

5 - 10 ANTILOCK BRAKE SYSTEM DIAGNOSIS


11/68

valve stem while a helper applies and releases thebrakes. I f the valve is operating correctly, the stemwill extend slightly when the brakes are applied andretract when the brakes are released. I f the valve isfaulty, replace the entire combination valve as an as-sembly.

TESTING PRESSURE DIFFERENTIAL SWITCH

(1) Have helper sit in drivers seat to apply brakepedal and observe red brake warning light.

(2) Raise vehicle on hoist.(3) Connect bleed hose to a rear wheel cylinder

and immerse hose end in container partially filledwith brake fluid.

(4) Have helper press and hold brake pedal to floorand observe warning light.

(a) I f warning light illuminates, switch is operat-

ing correctly.

(b) I f light fails to il luminate, check circuit fuse,

bulb and wiring. Repair as necessary and repeat

test steps (3) and (4).

(5) I f warning light still fails to il luminate, check

brakelight and parking brake switches and wiring

with test lamp. Repair or replace parts as necessaryand test differential pressure switch operation again.

(6) I f warning light still does not illuminate, switch

is faulty. Replace combination valve assembly, bleed

brake system and verify proper switch and valve op-

eration.

ANTILOCK BRAKE SYSTEM DIAGNOSIS 5 - 11


12/68

MASTER CYLINDERBRAKE FLUIDBRAKELINES

INDEX

page page

Brake Fluid Contamination . . . . . . . . . . . . . . . . . . 13Brakelines and Hoses . . . . . . . . . . . . . . . . . . . . . . 14Correct Brake Fluid Level . . . . . . . . . . . . . . . . . . . 12General Service Information . . . . . . . . . . . . . . . . . 12Importance of Clean Brake Fluid . . . . . . . . . . . . . . 12

Master Cylinder Bleeding . . . . . . . . . . . . . . . . . . . 13Master Cylinder Installation . . . . . . . . . . . . . . . . . . 14Master Cylinder Removal . . . . . . . . . . . . . . . . . . . 13Master Cylinder Reservoir Replacement . . . . . . . . 13Recommended Brake Fluid . . . . . . . . . . . . . . . . . . 12

GENERAL SERVICE INFORMATIONA two piece master cylinder is used on AN models.

The cylinder body containing the primary and sec-

ondary pistons is made of aluminum. The removable

flui d reservoir is made of nylon reinforced with glass

fiber (Fig. 1). The reservoir and grommets are the

only serviceable parts.

The fluid compartments of the nylon reservoir areinterconnected to permit fluid level equalization.

However, the equalization feature does not affect cir-

cuit separation in the event of a front/rear brake

malfunction. The reservoir compartments are de-

signed to retain the necessary quantity of fluid

needed to operate the functioning circuit.

Care must be exercised when removing/installing

the master cylinder brakelines. The threads in the

fluid ports can be damaged if care i s not exercised.

Start all brake line fittings by hand to avoid cross

threading.

The aluminum body section of the master cyl-

inder is not a repairable component. I f diagno-sis indicates that an internal malfunction hasoccurred, the aluminum body section must bereplaced as an assembly.

RECOMMENDED BRAKE FLUIDThe only brake fluid recommended for AN models

is Mopar brake fluid, or an equivalent fluid meetingSAE J 1703 and DOT 3 standards.

Use new brake fluid only, to top off the mas-

ter cylinder or refill the system. Never use re-

claimed fluid, unmarked or unspecified fluid,

fluid not meeting SAE/DOT standards, fluid

marked 70R1, or fluid from a container that has

been left open for any length of time. Using non

recommended or unspecified fluid can result in

brake failure after hard prolonged braking.

CORRECT BRAKE FLUID LEVELAlways clean the master cylinder reservoir and

caps before checking fluid level. I f not cleaned, dirt

could enter the fluid.

The fluid fill level is indicated on the driver side of

the master cylinder reservoir (Fig. 2).

The correct fluid level is to the bottom of the ring

indicators in the r eservoir filler openings. I f neces-

sary, add fluid to the proper level.

IMPORTANCE OF CLEAN BRAKE FLUIDThe RWAL /ABS antilock system brake fluid must

be clean and free of any type of contamination. For-

eign material in the fluid, or non-recommended fluid

will cause system malfunctions.

Clean the reservoir and caps thoroughly beforechecking level, or adding fluid. Cap open brakelinesand hoses during service to prevent dirt entry.

Dirt or foreign material circulating within the sys-tem will lead to component malfunctions.

Clean the reservoir and caps before checking leveland use clean, fresh brake fluid only.

Fig. 1 Two-Piece Master Cylinder Assembly

Fig. 2 Location Of Master Cylinder Fluid LevelInformation

5 - 12 MASTER CYLINDERBRAKE FLUIDBRAKELINES


13/68

BRAKE FLUID CONTAMINATIONOil in the fluid will cause brake system rubber

seals to soften and swell. The seals may also become

porous and begin to deteri orate.

I f fluid contamination is suspected, drain off a sam-

ple from the master cylinder. A suction gun or similar

device can be used for this purpose.

Empty the drained fluid into a glass container.Contaminants in the fluid will cause the fluid to sep-

arate into distinct layers. I f contamination has oc-

curred, the system rubber seals, hoses and cups must

be replaced and the system thoroughly flushed with

clean brake fluid.

MASTER CYLINDER REMOVAL(1) Disconnect brakeli nes at master cylinder (Fig.

2).

(2) Remove ground wire from combination valve

bracket (Fi g. 2).

(3) Remove nuts attaching master cylinder tomounting studs on power brake booster (Fig. 3).

(4) Sl ide combination valve bracket off cylindermounting studs. L oosen or disconnect brake lines atrear antilock valve and combination valve if neces-sary.

(5) Remove master cylinder.

MASTER CYLINDER RESERVOIR REPLACEMENT(1) Clean reservoir exterior and master cylinder

body.(2) Remove reservoir caps and drain all fluid from

reservoir.(3) Mount master cylinder in vise. Clamp vise jaws

on aluminum body.

(4) Note or mark position of reservoir before re-

moval. Side of reservoir with fluid level information

on it goes toward driver side of engine compartment.

(5) Remove reservoir by firmly r ocking it from side

to side (Fi g. 4). Continue rocking until reservoir

comes out of grommets.

(6) Remove and discard reservoir grommets.

(7) I nstall new reservoir grommets in master cylin-

der.

(8) L ubricate grommets with clean brake fluid.

CAUTION: The reservoir can be installed backwards

if care is not exercised. Install the reservoir so the

fluid fill information is facing the driver side of the

engine compartment (Fig. 2).

(9) Start reservoir into grommets. Rock reservoir

side to side until fully seated. Reservoir bottom sur-

face should touch grommets.

(10) Bleed master cylinder before installing it on

vehicle. Refer to procedure i n this section.

MASTER CYLINDER BLEEDINGMaster cylinder bleeding should be performed on

the bench before installation in the vehicle. Required

bleeding tools include bleed tubes and a wooden

dowel (Fi g. 5). The bleed tubes can be fabricated, or

purchased locally.

CYLINDER BLEEDING PROCEDURE(1) Remove protective caps from master cylinder

outlet ports and mount master cylinder assembly in

a vise.

(2) Attach bleed tubes to cylinder outlet ports and

insert bleed tubes in reservoir fluid compartments

(Fig. 4).(3) Fi ll reservoir with fresh Mopar DOT 3 brake

fluid.(4) Press cylinder pistons inward with wood dowel.

Then release pistons and allow them to r eturn underspring pressure.

Fig. 4 Removing/Installing Master CylinderReservoir

Fig. 3 Master Cylinder Mounting

MASTER CYLINDERBRAKE FLUIDBRAKELINES 5 - 13


14/68

(5) Continue bleeding operations until air bubbles

are no longer visible in fluid.

(6) Remove bleed tubes.

(7) I f cylinder will not be installed ri ght away, in-

stall protective caps in cylinder outlet ports. Caps

will keep dirt out of cylinder.

MASTER CYLINDER INSTALLATION(1) Position master cylinder on brake booster

mounting studs.

(2) Slide combination valve bracket onto cylinder

mounting studs.

(3) I nstall and tighten cylinder mounting nuts to

28 Nm (250 in. lbs.) torque.

(4) Connect brake lines to master cylinder. Tightenline fittings to 19 N m (170 in. lbs.) torque.

(5) Connect ground wire to combination valve

bracket.

(6) Tighten any brakelines at combination valve

and rear antilock valve, if loosened or disconnected.

(7) Fill and bleed brake system.

BRAKELINES AND HOSES

BRAKELINE AND HOSE INSPECTION

Flexible rubber hose is used at both front brakesand at the rear axle junction block. I nspect the hoseswhenever the brake system is serviced, at every en-gine oil change, or whenever the vehicle is i n for ser-

vice.I nspect the hoses for surface cracking, scuffing, orworn spots. Replace any brake hose immediately ifthe fabric casing of the hose is exposed due to cracksor abrasions.

Also check brake hose installation. Faulty installa-tion can result in kinked, twisted hoses, or contactwith the wheels and tires or other chassis compo-nents. All of these conditions can lead to scuffing,cracking and eventual failur e.

The steel brake lines should be inspected periodi-cally for evidence of corrosion, twists, kinks, leaks, orother damage. Heavily corroded li nes will eventually

rust through causing leaks. I n any case, corroded ordamaged brake lines should be replaced.

Brake line routing and connections are outlined inFigures 6, 7 and 8.

BRAKE LINE AND HOSE REPLACEMENT

Factory replacement brake l ines and hoses are rec-ommended to ensure quality, correct length and su-perior fatigue life. Care should be taken to make surethat brake line and hose mating surfaces are cleanand free from nicks and burrs. Also remember thatright and l eft brake hoses are not interchangeable.

Use new copper seal washers at all caliper connec-

tions (Fig. 7). Be sure brake line connections areproperly made (not cross threaded) and securelytightened.

Some front brake hoses have integral retainingclamps (Fig. 6). Be sure these clamps are properly at-tached as they keep the hose away from suspensioncomponents.

Fig. 5 Master Cylinder Bleeding



15/68

Fig. 6 Front Brakeline Routing

Fig. 7 Front Brakeline Connections

MASTER CYLINDERBRAKE FLUIDBRAKELINES 5 - 15


16/68

BRAKELINE EMERGENCY REPAIR

Mopar preformed replacement brakelines are recom-

mended and preferred for all repairs. However, double-

wall steel line can be used for emergency repair when

factory replacement parts are not readily available.Special, heavy duty tube bending and flaring equip-

ment is required to prepare double wall brake line.

Special bending tools are needed to avoid kinking or

twisting metal brake line. I n addition, special flaring

tools are needed to provide the inverted-type, double

flare required on metal brake lines.

Use F laring Tool C-4047 to provide the inverted,

double flare (Fig. 9). Heavy duty tube bending tools

are available through the dealer tool program.

Flaring Procedure

(1) Cut off damaged tube with Tubing CutterC-3478-A or an equivalent tool.

(2) Ream cut edges of tubing to ensure proper flare.

(3) I nstall replacement tube nut on section of tube

to be repaired.

(4) I nsert tube in flaring tool. Center tube in area

between vertical posts.

(5) Pl ace gauge form A over end of tube (Fig. 9).

(6) Push tubing through flaring tool jaws until tube con-

tacts recessed notch in gauge that matches tube diameter.

(7) Squeeze flaring tool jaws to lock tubing in place.

(8) I nsert plug on gauge A in tube. Then swingcompression disc over gauge and center tapered flar-ing screw in recess of compression disc.

(9) Tighten tool handle until plug gauge is seated onjaws of flaring tool. This will start inverted flare (Fig. 9).

(10) Remove plug gauge and complete invertedflare (Fig. 9).

(11) Remove flaring tools and verify that invertedflare is correct.

Fig. 9 Inverted Flare Tools

Fig. 8 Front Brakeline Connections (With ABS)



17/68

POWER BRAKE BOOSTERBRAKE PEDALSTOPLAMP SWITCH

INDEX

page page

Brake Pedal Installation . . . . . . . . . . . . . . . . . . . . . 18Brake Pedal Removal . . . . . . . . . . . . . . . . . . . . . . 18General Service Information . . . . . . . . . . . . . . . . . 17

Power Brake Booster Installation . . . . . . . . . . . . . . 18Power Brake Booster Removal . . . . . . . . . . . . . . . 17Stoplamp Switch Adjustment . . . . . . . . . . . . . . . . . 18

GENERAL SERVICE INFORMATIONAll AN models are equipped with power assist

brakes. A single diaphragm, power brake booster isused for all applications (Fig. 1).

The booster unit consists of a single housing dividedinto two chambers by a diaphragm. The outer edge ofthe diaphragm is secured to the housing. The boosterpush rod, which connects the booster to the brake pedaland master cylinder, is attached to the center of the di-

aphragm. A check valve is used in the booster outletconnected to the engine intake manifold. Power assist isgenerated by utilizing a combination of vacuum and at-mospheric pressure to boost brake assist.

The power brake booster is not a r epairable com-ponent. The booster must be replaced as an assem-bly if diagnosis indicates a malfunction hasoccurred.

A suspended-type brake pedal is used. The pedal is

attached to the pedal support bracket with a pivot

bolt and bushings (Fi g. 1). The booster push rod is

attached to the pedal with a clip. The pedal, bush-

ings, pivot pin and support bracket are all service-able components.

POWER BRAKE BOOSTER REMOVAL(1) Disconnect brakelines at master cylinder (Fi g. 2).

(2) Remove ground wire from combination valvebracket (F ig. 2).(3) Remove nuts attaching master cylinder to

mounting studs on power brake booster (Fi g. 2).(4) Slide combination valve bracket off cylinder

mounting studs. L oosen or disconnect brake lines atrear antilock valve and combination valve if necessary.

(5) Remove master cyli nder.

Fig. 1 Power Booster And Brake Pedal Components

POWER BRAKE BOOSTERBRAKE PEDALSTOPLAMP SWITCH 5 - 17


18/68

(6) Disconnect vacuum li nes at booster.

(7) Remove clip securing booster push rod to brake

pedal.

(8) Remove nuts from booster mounting studs.

(9) Remove booster and gasket from dash panel (Fi g.

1).

POWER BRAKE BOOSTER INSTALLATION(1) Position gasket on booster studs.

(2) Guide booster studs into dash panel holes and

seat booster on panel.(3) I nstall and tighten booster attaching nuts to 28

Nm (250 in. lbs.) torque.

(4) I nstall booster push rod on brake pedal. Secure

rod to pedal with retaining clip.

(5) I nstall booster check valve i f removed and con-

nect vacuum hose to check valve.

(6) Position master cylinder on brake booster

mounting studs.

(7) Slide combination valve bracket onto cylinder

mounting studs.

(8) I nstall and tighten cylinder mounting nuts to

28 N

m (250 in. lbs.) torque.(9) Connect brake lines to master cylinder. Tighten

line fittings to 19 N m (170 in. lbs.) torque.

(10) Connect ground wire to combination valve

bracket (Fi g. 3).

(11) Tighten any brakelines at combination valve

and rear antilock valve, if loosened or disconnected.

(12) Fill and bleed brake system.

BRAKE PEDAL REMOVAL(1) Remove clip securing booster push rod to brake

pedal (Fig. 1).

(2) Remove pedal pivot pin locknut and slide pinout of support bracket and pedal.

(3) Remove pedal and bushings.

BRAKE PEDAL INSTALLATION(1) I nspect pedal bushings. Replace bushings if

worn or damaged.

(2) L ubricate pedal bushings and pivot pin with Moparmulti mileage grease, L ubriplate, or a silicone grease.(3) I nstall bushings in pedal and position pedal in

support.(4) I nsert pivot pin through support and pedal

bushings. I nstall and tighten pivot pin locknut to 41Nm (30 ft. lbs.) torque.

(5) I nstall booster push rod on brake pedal and in-stall push rod retainer clip.

STOPLAMP SWITCH ADJUSTMENTThe stoplamp switch has a self adjusting feature.

An initial adjustment is only necessary when the

switch has been replaced, or removed for service ac-cess to other components.

SWITCH INITIAL ADJUSTMENT

(1) Push and hold brake pedal in applied position.(2) Push switch forward until fully seated against

bracket (F ig. 3).(3) Release brake pedal.(4) L ightly pull brake pedal rearward until master

cylinder push rod bottoms against master cylinder in-ternal stop. This action will set switch plunger atproper stroke l ength.

CAUTION: Do not use excessive force to move thepedal rearward and do not overextend the pedaland push rod.

Stoplamp Switch Replacement

(1) Remove steeri ng column opening cover.

Fig. 3 Stoplamp Switch Mounting

Fig. 2 Master Cylinder Mounting

5 - 18 POWER BRAKE BOOSTERBRAKE PEDALSTOPLAMP SWITCH


19/68

(2) Remove screws attaching air duct (that goesover steering column), to air conditioning/defrosteradapter duct. Then move air duct aside slightly foraccess to switch and bracket.

(3) U nseat switch wire harness plastic retainerfrom pedal support. Pull or pry retainer out of sup-port with pliers, or other suitable tool.

(4) Remove small nut and washer that attachesswitch bracket brake support.(5) P ush brake pedal forward, and work switch

and bracket out of support. Then disconnect switchwires and remove and switch and bracket as assem-bly.

(6) I f switch is to be replaced, transfer bracket tonew switch.

(7) Work switch and bracket up toward pedal sup-port and connect harness wires to switch.

(8) Position switch and bracket in support. I nstallbracket retaining nut and washer. Tighten nut to 7Nm (60 in. lbs.) torque. Be sure bracket tang isseated in support.

(9) Check switch operation before proceeding any

further. I f brakelights fail to illuminate or remain on,switch bracket is not seated, switch i s not fully en-gaged in mounting bracket, switch plunger is notaligned with striker, or wire harness is not fully con-nected. Reposition switch, bracket or striker asneeded.

(10) Align and install air duct and steering columncover.

POWER BRAKE BOOSTERBRAKE PEDALSTOPLAMP SWITCH 5 - 19


20/68

DRUM BRAKES

INDEX

page page

Brake Drum Installation . . . . . . . . . . . . . . . . . . . . . 23Brake Drum Refinish Limits . . . . . . . . . . . . . . . . . . 22Brake Drum Refinishing . . . . . . . . . . . . . . . . . . . . 22Brake Drum Removal . . . . . . . . . . . . . . . . . . . . . . 20Brake Drum Runout . . . . . . . . . . . . . . . . . . . . . . . 23Brake Support Plate Installation . . . . . . . . . . . . . . . 23Brake Support Plate Removal . . . . . . . . . . . . . . . . 23Brakeshoe Installation . . . . . . . . . . . . . . . . . . . . . . 21

Brakeshoe Removal . . . . . . . . . . . . . . . . . . . . . . . 20Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . 21General Information . . . . . . . . . . . . . . . . . . . . . . . 20Rear Drum Brake Adjustment . . . . . . . . . . . . . . . . 24Wheel Cylinder Installation . . . . . . . . . . . . . . . . . . 24Wheel Cylinder Overhaul . . . . . . . . . . . . . . . . . . . . 24Wheel Cylinder Removal . . . . . . . . . . . . . . . . . . . . 24Wheel Nut Tightening . . . . . . . . . . . . . . . . . . . . . . 25

GENERAL INFORMATIONThe drum brake units used for all applications are

dual shoe, internal expanding units with an auto-

matic self adjusting mechanism (Figs. 1 and 2). Nine

inch brakes are used on standard models. Ten inch

brakes are used on models with heavy duty optionpackages.

Cast wheel cylinders are used for all applications.

The cylinders are serviceable components and can be

overhauled. The cylinder bores can be lightly

polished with crocus cloth but must not be

honed.

BRAKE DRUM REMOVAL(1) Raise vehicle and remove wheel and ti re.(2) Remove clip nuts securing brake drum to wheel

studs.(3) I f drum i s difficult to remove, retract brake-

shoes as follows:

(a) Remove rear plug from access hole in support

plate.

(b) I nsert thin screwdriver into access hole and

push adjuster lever away from adjuster screw star

wheel.

(c) I nsert Adjusting Tool C-3784 into brake ad-

justing hole and turn adjuster star wheel to retract

brakeshoes.(4) Remove brake drum.

(5) I nspect brakelining for wear, misalignment, or

evidence of leakage from axle or wheel cyli nder.

BRAKESHOE REMOVAL(1) Remove rear wheel and brake drum.

(2) Remove shoe return springs with Brake Spring

Plier Tool C-3785 (Fig. 3).

(3) Remove adjuster cable. Slide cable eye off an-

chor pin. Then unhook and remove cable from ad-juster lever.

Fig. 1 Nine-Inch Brake Assembly

Fig. 2 Ten-Inch Brake Assembly

5 - 20 DRUM BRAKES


21/68

(4) Remove cable guide from secondary shoe and

anchor plate from anchor pin.(5) Remove adjuster lever. Disengage l ever from

spring by sliding lever forward to clear pivot and

work lever out from under spring.

(6) Remove adjuster lever spring from pivot.

(7) Disengage and remove shoe spring from brake-

shoes.

(8) Disengage and remove adjuster screw assembly

from brakeshoes.

(9) Remove brake shoe retainers, springs and pins

with Brake Spring P lier Tool C-4070, (F ig. 4).

(10) Remove secondary brakeshoe from support

plate.

(11) Remove strut and anti rattle spring (Fig. 5).

(12) Remove parking brake lever from secondary

shoe.

(13) Remove primary shoe from support plate.

(14) Disengage parki ng brake lever from parking

brake cable.

CLEANING AND INSPECTIONClean the brake components, including the support

plate and wheel cylinder exterior, with a water

dampened cloth or with Mopar brake cleaner. Do not

use any other cleaning agents.

Replace the brakeshoes if riveted lining is worn to

within 0.78 mm (0.031 in.) of the ri vet heads, or if

bonded lining is less than 1.59 mm (0.062 in.) thick.

Examine the l ining contact pattern to determine if

the shoes are bent or the drum is tapered. The lining

should exhibit contact across the entire lining width.Shoes exhibiting contact only on one side should bereplaced and the drum checked for runout or taper.

Clean and inspect the adjuster screw assembly. Re-place the assembly if the star wheel threads aredamaged, or the components are severely rusted orcorroded.

Discard the brake springs and retainer componentsif worn distorted, or collapsed. Also replace thesprings if a brake drag condition had occurred. Over-heating wil l distort and weaken the springs.

I nspect the brakeshoe contact pads on the supportplate (Fig. 6). Remove light rust and scale from the

pads with fine sandpaper. However, replace the sup-port plate i f any of the pads are worn or rustedthrough. Also replace the plate if it is bent or dis-torted.

BRAKESHOE INSTALLATION(1) L ubricate anchor pin and brakeshoe contact

surfaces of support plate (Fig. 6). Use Mopar multi-purpose grease, bearing grease, or L ubriplate.

(2) L ubricate adjuster screw socket, nut, buttonand screw thread surfaces with Mopar spray lube orL ubriplate.

Fig. 3 Removing/Installing Shoe Return Springs

Fig. 4 Removing/Installing Shoe Retainers, Springs

and Pins

Fig. 5 Removing/Installing Strut And Spring

DRUM BRAKES 5 - 21


22/68

(3) Attach parking brake cable to lever. Then con-

nect lever to secondary shoe. Use new U-clip to se-

cure lever.

(4) I nstall primary shoe on support plate. Secureshoe with new holddown spring, retainers and pin

(Fig. 7).

(5) I nstall spring on parking brake strut and en-

gage strut in primary shoe (Fig. 7).

(6) I nstall secondary shoe on support plate (Fig. 7).

I nsert strut in shoe and guide shoe onto anchor pin.Secure shoe with new holddown spring, retainers andpin.

(7) I nstall anchor plate on support plate anchorpin.

(8) I nstall adjuster cable eyelet on anchor pin.(9) L ubricate and assemble adjuster screw compo-

nents (Fig. 8). Then install and engage adjusterscrew in brakeshoes. Be sure adjuster screw starwheel is positioned closest to rear shoe.

CAUTION: Be sure the adjuster screws are installedon the correct brake unit. The adjuster screws are

marked L (left) and R (right) for identification (Fig.

8). The passenger side adjuster screw has left hand

threads and the driver side screw has right hand

threads.

(10) I nstall adjuster lever spring on rear shoe pin.

Position adjuster l ever on pin and slide hooked end of

spring over lever to hold it in place.

(11) Raise adjuster lever upward and attach ad-

juster cable spring to lever. Be sure spring is securely

attached to lever and that lever remains seated on

shoe pin.

(12) Connect the shoe spring to l ower part of each

brakeshoe. Hooked end of spring goes in rear shoe.

(13) I nstall cable guide in secondary shoe and po-

sition cable around guide.

(14) I nsert hooked end of rear shoe return spring

through cable guide and into spring hole in brake-shoe. Then seat spring on anchor pin with brakespring pliers.

(15) I nstall front shoe return spring.

(16) Verify adjuster operation. Pull adjuster cableupward. Cable should lift lever and rotate startwheel when cable is released. Be sure adjuster leverproperl y engages star wheel teeth.

(17) Adjust brakeshoes to drum with brake gaugeas described in Service Adjustments section.

BRAKE DRUM REFINISHINGThe brake drums can be resurfaced on a drum

lathe when necessary. I niti al machini ng cuts shouldbe limited to 0.12 mm (0.005 in.) at a time as heavierfeed rates can produce taper and surface variation.F inal fini sh cuts of 0.025 - 0.038 mm (0.001 - 0.0015

in.) are recommended and will provide the best sur-face finish.

Refinishing a drum with hard spots is not recom-mended. This type of drum should be replaced.

Be sure the drum is securely mounted in the lathebefore machining operations. A damper strap shouldalways be used around the drum to reduce vibrationand avoid chatter marks.

BRAKE DRUM REFINISHLIMITSThe maximum allowable diameter of the drum

braking surface is usually stamped or cast into the

Fig. 6 Shoe Contact Surfaces On Support Plate

Fig. 7 Brakeshoe Installation

Fig. 8 Adjuster Screw Components

5 - 22 DRUM BRAKES


23/68

drum outer edge (Fig. 9). Generally, a nine inch drum

can be machined to a maximum of 230.1 mm (9.060

in.) and a ten i nch drum to 255.5 mm (10.060 in.). Al -

ways replace the drum if machining would cause

drum diameter to exceed indicated size limit.

BRAKE DRUM RUNOUT

Measure drum diameter and runout with an accu-rate gauge. The most accurate method of measure-

ment involves mounting the drum i n a brake lathe

and checking variation and runout with a dial indi-

cator. Variations i n drum diameter should not exceed

0.076 mm (0.003 in). Drum runout should not exceed

0.20 mm (0.008 i n) out of round. Refinish the drum if

runout or variation exceed these values.

BRAKE DRUM INSTALLATION(1) Clean drum with Mopar brake cleaning solvent

or with a soap and water solution only. Do not use

any other cleaning agents.(2) Adjust brake shoes to drum. Turn adjuster

screw star wheel in small increments until drum is

slip fit on shoes.

(3) I nstall and secure drum to wheel studs with

new clip nuts.

(4) I nstall rubber access plugs in support plate if

removed.

(5) I nstall wheel and tire.

BRAKE SUPPORTPLATEREMOVAL(1) Remove wheel and ti re and brake drum.

(2) Remove axle shaft and retainer. Refer to Gr oup

3 for procedures.

(3) Remove pri mary brakeshoe for access to park-

ing brake cable if necessary.

(4) Compress parking brake cable retainer tabs

with a hose clamp (Fig. 10). T hen push retainer and

cable through and out of support plate.

(5) Disconnect brake li ne at wheel cylinder.

(6) Remove wheel cylinder and brakeshoes from

support plate.

(7) Remove bolts attaching support plate to axle

and remove support plate.

BRAKE SUPPORTPLATEINSTALLATION(1) I f new support plate is being installed, apply

bead of sili cone sealer around wheel cylinder mount-

ing surface. Then transfer wheel cylinder to new sup-

port plate.

(2) L ubricate brake shoe contact surfaces of sup-

port plate with Mopar multi mileage grease.

(3) Apply bead of silicone sealer around axle

mounting surface of support plate.

(4) I nstall support plate on axle flange. Tighten at-

taching bolts to 47-81 Nm (35-60 ft. lbs.).

(5) I nstall brakeshoes.(6) I nstall parking brake cable i n support plate.

(7) I nstall axle shaft and retainer.

(8) Start brakeline in wheel cylinder and install

cylinder on support plate. Tighten brakeline fitting

after cylinder installation.

(9) Connect parki ng brake cable to lever on second-

ary shoe and install brakeshoes on support plate.

(10) Adjust brakeshoes to drum with brake gauge.

(11) I nstall brake drum and wheel and tire.

(12) Bl eed brake system.

Fig. 9 Location Of Brake Drum Maximum AllowableDiameter

Fig. 10 Removing Parking Brake Cable FromSupport Plate

DRUM BRAKES 5 - 23


24/68

WHEEL CYLINDER REMOVAL(1) Raise vehicle and remove wheel and brake

drum.

(2) Disconnect brakeline at wheel cylinder.

(3) Remove brakeshoe return springs and move

shoes out of engagement with cyli nder push rods.

(4) Remove cylinder attaching bolts and remove

cylinder from support plate.

WHEEL CYLINDER OVERHAUL

WHEEL CYLINDER DISASSEMBLY (FIGS. 11

AND 12).

(1) Remove push rods and boots.

(2) Push pistons, cups and expander spring out of

cyli nder bore.

(3) Remove cylinder bleed screw.

WHEEL CYLINDER CLEANING AND

INSPECTIONClean the cylinder and pistons with clean brake

fluid or brake cleaner only. Do not use any other

cleaning agents. Dry the cylinder and pistons with

compressed air. Do not use rags or shop towels to dry

the cylinder components. L int from cloth materials

will adhere to the cylinder bores and pistons.

I nspect the cylinder bore. L ight discoloration and

dark stains in the bore are normal and will not im-

pair cylinder operation. I f desired, the bore can be

lightly polished but only with crocus cloth. Replace

the cylinder if the bore is scored, pitted or heavily

corroded. Honing the bore to restore the surface is

not recommended.

I nspect the cylinder pistons. The piston surfaces

should be smooth and free of scratches, scoring and

corrosion. R eplace the pistons if worn, scored, or cor-roded. Do not attempt to restore the surface by sand-

ing or polishing.Discard the old piston cups and the spring and ex-

pander. These parts are not reusable. The originaldust boots may be reused but only if in good condi-tion.

ASSEMBLING WHEEL CYLINDER

(1) L ubricate wheel cylinder bore, pistons, pistoncups and expander spring with fresh brake fluid.

(2) I nstall first piston i n cylinder bore. Then i nstallcup in bore and against piston. Be sure lip of pis-ton cup is facing inward (toward spring and ex-pander) and flat side is against piston.

(3) I nstall expander spring followed by remainingpiston cup and piston.

(4) I nstall boots on each end of cylinder and insertpush rods in boots. Press boots onto cylinder ends invise if necessary.

(5) I nstall cylinder bleed screw.

WHEEL CYLINDER INSTALLATION(1) Apply small bead of Mopar silicone sealer

around cylinder mounting surface of support plate.(2) Start brakeline fitting i n cylinder by hand.(3) Mount cylinder on support plate and install cyl-

inder attaching bolts.

(4) Tighten brakeline fitting in wheel cylinder.(5) I nstall wheel brake components.(6) I nstall brake drum and wheel.(7) Bl eed brakes.(8) L ower vehicle.

REAR DRUM BRAKE ADJUSTMENTThe rear drum brakes are equipped with a self ad-

justing mechanism. Under normal circumstances, theonly time adjustment is required is when the brake-shoes are replaced, removed for access to other parts,or when one or both drums are replaced.

Adjustment can be performed with a standardbrake gauge, or with Adjusting Tool C-3784. Bothmethods are descri bed in the following procedures.

ADJUSTMENT WITH BRAKE GAUGE

(1) Verify that the left/right automatic adjuster le-ver and cable are properly connected. Al so verify thatthe parking brakes are fully released and the cablesare slack.

(2) I nsert the brake gauge in the drum. Expandthe gauge until the gauge inner legs contact thedrum braking surface. Then lock the gauge i n posi-tion (Fig. 13).

Fig. 11 Wheel Cylinder Components (Nine-InchBrake)

Fig. 12 Wheel Cylinder Components (Ten-InchBrake)

5 - 24 DRUM BRAKES


25/68

(3) Reverse the gauge and i nstall it on the brake-

shoes (Fig. 4). Position the gauge legs at the shoe

centers as shown. I f the gauge does not fit (too l oose/too tight), adjust the shoes.

(4) Pull the shoe adjuster star wheel away from

the automatic adjuster lever.

(5) Turn the adjuster star wheel (by hand) to ex-

pand or retract the brakeshoes. Continue adjustment

until the gauge outside legs are a light drag-fit on

the shoes (Fig. 14).

(6) Repeat adjustment at the opposite brakeshoe

assembly.

(7) I nstall the brake drums and wheels and lower

the vehicle.

(8) Make final adjustment. Dri ve vehicle and make

one forward stop foll owed by one reverse stop. Repeat

procedure 8-10 times to actuate adjuster mechanism

and equalize adjustment. Bring vehicle to complete

standstill at each stop. I ncomplete, rolling stops wil l

not activate the automatic adjusters.

ADJUSTMENT WITH TOOL C-3784

(1) Release parking brakes fully, if applied. Be sure

there is slack in the cables.

(2) Raise vehicle so rear wheels are free to turn.

(3) Remove rubber plugs fr om access holes in rear

brake support plates.

(4) I nsert Drum Brake Adjusting Tool C-3784

through access hole and engage it in adjuster screwstar wheel. Turn star wheel counterclockwise (move

tool upward) until a slight drag is felt when road

wheel is rotated.

(5) I nsert a thin screwdriver or length of welding

rod into support plate access hole and push adjuster

lever out of engagement with star wheel (Fi g. 15). Do

not bend the lever or distort the lever spring.

(6) Hold adjuster lever away from star wheel. T hen

back off star wheel until shoe drag on drum is elim-

inated.

(7) Repeat above adjustment at the opposite wheel.

Be sure adjustment is equal.

(8) I nstall access hole plugs in support plate.

(9) Adjust the parki ng brake after wheel brake ad-

justment.

(10) M ake final adjustment. Drive vehicle and

make one forward stop followed by one reverse stop.

Repeat procedure 8-10 times to actuate adjuster

mechanism and equalize adjustment. Bring vehicle to

complete standstill at each stop. I ncomplete, rolli ng

stops will not activate the automatic adjusters.

WHEEL NUT TIGHTENINGThe wheel attaching nuts must be tightened prop-

erly to ensure efficient brake operation. Overtighten-

ing, or uneven tightening can distort brake drums.

I mpact wrenches are not recommended for tight-

ening wheel nuts. A torque wrench should be used

for this purpose at all times.

Fig. 13 Adjusting Gauge To Brake Drum

Fig. 14 Adjusting Brakeshoes To Gauge

Fig. 15 Adjusting Rear Brakeshoes With Tool C-3784

DRUM BRAKES 5 - 25


26/68

The correct tightening sequence is important in

avoiding drum distorti on. The correct sequence is in

a diagonal crossing pattern.

Seat the wheel and install the wheel nuts finger

tight. Tighten the nuts in sequence to 1/2 the re-

quired torque. Then repeat the tightening sequence

to final specifi ed torque.

5 - 26 DRUM BRAKES


27/68

DISC BRAKES2-WHEEL DRIVE

INDEX

page page

Brakeshoe Installation . . . . . . . . . . . . . . . . . . . . . . 29Brakeshoe Removal . . . . . . . . . . . . . . . . . . . . . . . 28Caliper Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 32Caliper Cleaning and Inspection . . . . . . . . . . . . . . 31

Caliper Disassembly . . . . . . . . . . . . . . . . . . . . . . . 30Caliper Installation . . . . . . . . . . . . . . . . . . . . . . . . 32Caliper Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 30General Information . . . . . . . . . . . . . . . . . . . . . . . 27

GENERAL INFORMATIONTwo-wheel drive AN models are equipped with sin-

gle piston disc brake calipers. The calipers move lat-erally on pins that attach the caliper to the mountingadapter. Abutment surfaces machined in the brake-shoes and mounting adapter maintain fore and aftalignment. The calipers are full y serviceable compo-nents and can be overhauled when necessary.

Non metallic caliper pistons are used for all appli-cations. The pistons are made of a phenolic resin ma-terial.

Two-wheel drive models are equipped with a discbrake r otor and hub assembly. The rotor hub i s sup-ported on the steering knuckle spindle by the wheelbearings. The rotor braking surfaces are ventilatedand can be machined to restore surface fi nish whennecessary.

The disc brakeshoes are held in position by retain-ing springs. The inboard shoe spring is an integralpart of the shoe. The outboard shoe is spring is re-movable. Two slide pins secure the caliper to the cal-

iper adapter. The adapter, which is also removable, isattached to the steering knuckle (Fig. 1).

DISC BRAKELINING WEAR COMPENSATION

The caliper piston seal controls the amount of pis-

ton extension needed to compensate for normal lining

wear.

I n operation, the seal is deflected outward under

fluid pressure (Fi g. 2). When fluid pressure is re-

leased, the seal relaxes and retracts the piston. T he

amount of retraction is determined by lining wear.

Generally, the amount is just enough to maintaincontact between the piston and inboard shoe and a

zero or very slight clearance at the rotor.

The fluid level in the disc brake reservoir will de-

crease as l ining wear occurs. This is a normal condi-

tion and only requires that enough fluid be added to

restore proper level.

SHOE AND LINING WEAR LIMITS

Combined shoe and lining thickness should be

measured at the thinnest part of the assembly. Re-

Fig. 1 Disc Brake Components (2-Wheel Drive)

DISC BRAKES2-WHEEL DRIVE 5 - 27


28/68

place the brakeshoes when overall thickness is ap-

proximately 6 mm (1/4 in.) or less.

The brakeshoes are replaceable components

but must be replaced on both front wheels at

the same time. This is necessary to maintain

braking balance. Never replace the shoes on

one side only. Replacing the shoes at only one

wheel will cause uneven braking and pull.

BRAKESHOE REMOVAL(1) Clean master cylinder reservoir and fil ler caps.

(2) Remove filler caps and drain approximately 1/4

of fluid fr om reservoir. U se clean suction gun or sim-il ar device to remove fluid.

(3) Raise and support front of vehicle.(4) Remove front wheel and tire assemblies.(5) Remove outboard retaining spring from caliper

(Fig. 3). Push spring ends downward and pull springends out of cali per to r emove.

(6) Bottom each caliper piston with large C-clamp.Position clamp frame on rear of caliper and position

clamp screw on outboard brakeshoe. Then tighten

clamp until piston is bottomed i n caliper bore.

(7) Remove caliper slide pins (Fig. 4). Use 3/8 in.

or 10 mm socket to remove pins, as necessary.

(8) L ift caliper and i nboard brakeshoe upward out

of adapter and off rotor (Fig. 5).

(9) Support caliper on box, mechanics stool, or se-

cure it to chassis with wire. Do not allow brake hose

to support caliper weight.

(10) Remove outboard shoe from adapter or from

caliper (Fi g. 6).

(11) Remove inboard shoe from caliper (Fig. 7). Tilt

shoe outward until retainer springs clear piston and

remove shoe.

Fig. 2 Piston Seal Wear Compensation

Fig. 3 Removing Outboard Shoe Spring

Fig. 4 Caliper Mounting

Fig. 5 Caliper And Brakeshoe Removal

5 - 28 DISC BRAKES2-WHEEL DRIVE


29/68

BRAKESHOE AND CALIPER INSPECTION

I nspect condition of the outboard shoe spring (Fi g.

3). Replace the spring if bent, distorted, or broken.

I nspect the brakeshoes (Fi g. 8). Replace the shoesif the lining material is worn, cracked, or burned.Also replace the shoes if bent, warped, or if the in-board shoe retainer spring is damaged.

I nspect condition of the shoe tangs (Fig. 8). Thetang notches are important as they position the shoesin the adapter. The tangs also allow the shoes toslide on the adapter ledge surface for wear adjust-

ment. Replace the shoes as a set if a tang on eithershoe is bent, worn, or damaged.

I nspect the area around the caliper boot, pistonand interior of the caliper frame (Fig. 9). I f evidenceof fluid leakage in this area is noted, the caliper willrequire overhaul to correct the l eak.

I nspect condition of the caliper piston dust boot(Fig. 9). I f the boot is cut, cracked, or torn, an over-haul is required to replace the boot.

I nspect the caliper slide pins, slide pin bushingsand boots (Fig. 10). Replace any of these parts ifworn or damaged.

BRAKESHOE INSTALLATION(1) Clean and lubricate slide surfaces of caliper

mounting adapter (Fig. 11). Use wire brush to cleansurfaces. T hen apply coating of Mopar multi mileagegrease to slide surfaces and to threads of slide pinholes.

(2) Clean caliper slide pins with brake cleaner orbrake fluid. Then apply coating of silicone grease topins. Minor rust or corrosion can be polishedfrom pins with crocus cloth. However, replace

Fig. 6 Outboard Brakeshoe Removal/Installation

Fig. 7 Inboard Brakeshoe Removal/Installation

Fig. 8 Disc Brakeshoe Inspection Points

Fig. 9 Caliper Inspection Points

Fig. 10 Caliper Slide Pin, Bushing And Boot



30/68

the pins if severely rusted, or corroded.

(3) I nstall caliper slide pin bushings and boots if

removed (Fig. 10).

(4) I nstall inboard shoe (Fi g. 7). Be sure spring is

full y seated in caliper piston.

(5) Install outboard shoe in caliper mounting

adapter.

(6) Carefully lower caliper into place over rotor

and outboard brakeshoe.

(7) Align caliper in adapter and start caliper slide

pins by hand. Do not cross thread pins.

(8) Check position of brakeshoes (Fig. 12). Verify

that shoe tabs are squarely seated on ledge surfaces

of caliper adapter.

(9) Final-tighten caliper slide pins to 25-35 Nm

(18-26 ft. lbs.).

(10) I nstall outboard shoe spring (Fig. 13). Be sure

spring is hooked under each adapter ledge and that

spring ends are fully seated in caliper holes asshown.

(11) I nstall wheel and tire assemblies.(12) L ower vehicle.(13) Top off master cylinder fluid level.(14) Apply brakes several times to seat caliper pis-

tons and brakeshoes. Be sure firm pedal is obtainedbefore moving vehicle.

CALIPER REMOVAL(1) Raise vehicle and remove front wheels.

(2) Remove outboard shoe spring (Fi g. 3).

(3) Disconnect brake hose at caliper. Discard hose

fitting washers if worn, or damaged (F ig. 14).

(4) Remove caliper slide pins.

(5) Remove cali per and brakeshoes from r otor and

adapter.

CALIPER DISASSEMBLY(1) Remove brakeshoes from caliper (Figs. 6 and

7). Discard shoes if worn, or damaged.

(2) Drain old brake fluid out of caliper into drain

pan.

(3) Remove piston dust boot (Fig. 15). Use screw-driver to push boot out of groove.

(4) Pad outboard shoe side of caliper interior with

a minimum 2.54 cm (1 in.) thickness of shop towels

(Fig. 16). Towels will prevent piston damage when

piston is comes out of bore.

(5) Remove caliper piston with short bursts of com-

pressed air. Apply air pressure through fluid inlet

port of caliper (F ig. 16).

Fig. 11 Caliper Adapter Slide Surfaces

Fig. 12 Checking Brakeshoe Seating

Fig. 13 Correct Position Of Outboard Shoe Spring

Fig. 14 Caliper Brake Hose Connection

5 - 30 DISC BRAKES2-WHEEL DRIVE


31/68

CAUTION: Do not blow the piston out of the caliper.

This procedure will usually result in severe pistondamage. Use only enough air pressure to ease thepiston out of the bore. In addition, never attempt tocatch the piston as it leaves the caliper bore. This

practice will result in personal injury.

(6) Remove caliper piston seal with wood pencil or

plastic tool (Fig. 17). Do not use metal tools as they

will scratch piston bore.

(7) Remove caliper slide pin bushings and boots

(Fig. 18).

CALIPER CLEANINGAND INSPECTIONClean the caliper and piston with clean brake fluid

or Mopar brake cleaning solvent only. Do not use gas-

oline, kerosene, thinner, or any similar type of sol-

vent. These products will leave a residue that could

damage the piston, seal, or piston bore.

Wipe the caliper and piston dry with lint free tow-

els or use low pressure compressed air.

I nspect the piston and piston bore. Replace the cal-

iper if the bore is corroded, r usted, or scored. Do not

hone the caliper piston bore. Replace the caliper if

the bore is damaged.

I nspect the caliper piston (Fig. 18). The piston is

made from a phenolic resin (plastic material) and

should be smooth and clean. Replace the piston if

cracked or scored. Do not attempt to restore a scored

piston surface by sanding or polishing. The piston

must be replaced if damaged.

CAUTION: If the caliper piston must be replaced, in-

stall the same type of piston in the caliper. Never

interchange phenolic resin and steel caliper pis-tons. The pistons, seals, seal grooves, caliper bores

and piston tolerances are different for resin and

steel pistons and calipers. Do not intermix these

components at any time.

I nspect the caliper bushings and boots. Replace the

boots if cut or torn. Clean and lubricate the bushings

with GE 661, Dow 111, or similar silicone grease if

necessary.

Fig. 15 Removing Piston Dust Boot

Fig. 16 Caliper Piston Removal

Fig. 17 Removing Caliper Piston Seal



32/68

CALIPER ASSEMBLY(1) L ubricate slide pin boots and bushings with

GE, or Dow silicone grease. Then install boots and

bushings in caliper.

(2) Coat caliper piston bore, piston and new piston

seal with fresh brake fluid.

(3) I nstall new piston seal in caliper bore. Press

seal into groove with finger (Fig. 19). L ubricate seal

and caliper bore with additional, fresh brake fluid af-

ter seal installation.

(4) Apply light coat of GE 661, Dow 111 or similar

silicone g

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