servo CHRYSLER VOYAGER 1996 Service Manual

MAINTENANCE SCHEDULES
INDEX
page page
GENERAL INFORMATION
INTRODUCTION......................... 3
SCHEDULE ± A.......................... 3SCHEDULE ± B.......................... 4
UNSCHEDULED INSPECTION............... 3
GENERAL INFORMATION
INTRODUCTION
Service and maintenance procedures for compo-
nents and systems listed in Schedule ± A or B can be
found by using the Group Tab Locator index at the
front of this manual. If it is not clear which group
contains the information needed, refer to the index at
the back of this manual.
There are two maintenance schedules that show
proper service based on the conditions that the vehi-
cle is subjected to.
Schedule ±A, lists scheduled maintenance to be
performed when the vehicle is used for general trans-
portation.
Schedule ±B, lists maintenance intervals for vehi-
cles that are operated under the conditions listed at
the beginning of the Maintenance Schedule section.
Use the schedule that best describes your driving
conditions.
Where time and mileage are listed, follow the
interval that occurs first.
UNSCHEDULED INSPECTION
At Each Stop for Fuel
²Check engine oil level, add as required.
²Check windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, brake
master cylinder, power steering and transaxle and
add as needed.
²Check all lights and all other electrical items for
correct operation.
²Check rubber seals on each side of the radiator
for proper fit.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses
²Inspect the CV joints and front suspension com-
ponents
²Rotate the tires at each oil change interval
shown on Schedule ± A (7,500 miles) or every other
interval shown on Schedule ± B (6,000 miles).
²Check the coolant level, hoses, and clamps.
²If your mileage is less than 7,500 miles (12 000
km) yearly, replace the engine oil filter at each oil
change.
²Replace engine oil filter on 2.4L engines.
SCHEDULE ± A
7,500 Miles (12 000 km) or at 6 months
²Change engine oil.
15,000 Miles (24 000 km) or at 12 months
²Change engine oil.
²Replace engine oil filter.
22,500 Miles (36 000 km) or at 18 months
²Change engine oil.
²Inspect brake linings.
30,000 Miles (48 000 km) or at 24 months
²Change engine oil.
²Change automatic transmission fluid.
²Replace engine oil filter.
²Replace air cleaner element.
²Inspect tie rod ends and boot seals.
37,500 Miles (60 000 km) or at 30 months
²Change engine oil.
45,000 Miles (72 000 km) or at 36 months
²Change engine oil.
²Replace engine oil filter.
²Inspect brake linings.
²Flush and replace engine coolant at 36 months,
regardless of mileage.
NSLUBRICATION AND MAINTENANCE 0 - 3

MAINTENANCE SCHEDULES
INDEX
page page
GENERAL INFORMATION
MAINTENANCE SCHEDULE............... 2
MAINTENANCE SCHEDULEÐ
DIESEL ENGINE....................... 2SCHEDULEÐA (DIESEL).................. 2
SCHEDULEÐB (DIESEL).................. 3
UNSCHEDULED INSPECTION.............. 2
GENERAL INFORMATION
MAINTENANCE SCHEDULE
Refer to the 1998 GS Service Manual for Gasoline
Engine and non-engine related Maintenance Sched-
ules.
MAINTENANCE SCHEDULEÐDIESEL ENGINE
The following are engine related Maintenance
items which are unique to Diesel engine-equipped
vehicles. Refer to the 1998 GS Service Manual for
Gasoline Engine and non-engine related Maintenance
Schedules.
The service intervals are based on odometer read-
ings in kilometers. There are two maintenance sched-
ules that show proper service intervals. Use the
schedule that best describes the conditions the vehi-
cle is operated under.Schedule-Alists all the sched-
uled maintenance to be performed under normal
operating conditions.Schedule-Bis the schedule for
vehicles that are operated under one or more of the
following conditions:
²Day and night temperatures are below freezing.
²Stop and go driving.
²Long periods of engine idling.
²Driving in dusty conditions.
²Short trips of less than 5 miles.
²Operation at sustained high speeds during hot
weather above 32ÉC (90ÉF).
²Taxi, police or delivery service.
²Trailer towing.
UNSCHEDULED INSPECTION
At Each Stop for Fuel
²Check engine oil level, add as required.
²Check windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.²Check fluid levels of coolant reservoir, brake
master cylinder, power steering and transaxle and
add as needed.
²Check all lights and all other electrical items for
correct operation.
²Check rubber seals on each side of the radiator
for proper fit.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses
²Inspect the CV joints and front suspension com-
ponents
²Rotate the tires at each oil change interval
shown on ScheduleÐA (7,500 miles) or every other
interval shown on ScheduleÐ B (6,000 miles).
²Check the coolant level, hoses, and clamps.
²If your mileage is less than 7,500 miles (12 000
km) yearly, replace the engine oil filter at each oil
change.
²Replace engine oil filter.
SCHEDULEÐA (DIESEL)
1 000 KM
²Change engine oil.
²Change engine oil filter.
²Check all fluid levels.
²Check correct torque, intake manifold mounting
nuts.
²Check correct torque, exhaust manifold mount-
ing nuts.
²Check correct torque, turbocharger mounting
nuts.
²Check correct torque, water manifold bolts.
10 000 KM
²Change engine oil.
²Change engine oil filter.
20 000 KM
²Change engine oil.
²Change engine oil filter.
²Replace air filter element.
0 - 2 LUBRICATION AND MAINTENANCENS/GS

CONDITION POSSIBLE CAUSES CORRECTION
Road Wander 1. Incorrect tire pressure 1. Inflate tires to recommended
pressure
2. Incorrect front or rear wheel toe 2. Check and reset wheel toe
3. Worn wheel bearings 3. Replace wheel bearing
4. Worn control arm bushings 4. Replace control arm bushing
5. Excessive friction in steering gear 5. Replace steering gear
6. Excessive friction in steering shaft
coupling6. Replace steering coupler
7. Excessive friction in strut upper
bearing7. Replace strut bearing
Lateral Pull 1. Unequal tire pressure 1. Inflate all tires to recommended
pressure
2. Radial tire lead 2. Perform lead correction procedure
3. Incorrect front wheel camber 3. Check and reset front wheel
camber
4. Power steering gear imbalance 4. Replace power steering gear
5. Wheel braking 5. Correct braking condition causing
lateral pull
Excessive Steering Free Play 1. Incorrect Steering Gear Adjustment 1. Adjust Or Replace Steering Gear
2. Worn or loose tie rod ends 2. Replace or tighten tie rod ends
3. Loose steering gear mounting bolts 3. Tighten steering gear bolts to
specified torque
4. Loose or worn steering shaft
coupler4. Replace steering shaft coupler
Excessive Steering Effort 1. Low tire pressure 1. Inflate all tires to recommended
pressure
2. Lack of lubricant in steering gear 2. Replace steering gear
3. Low power steering fluid level 3. Fill power steering fluid reservoir to
correct level
4. Loose power steering pump drive
belt4. Correctly adjust power steering
pump drive belt
5. Lack of lubricant in ball joints 5. Lubricate or replace ball joints
6. Steering gear malfunction 6. Replace steering gear
7. Lack of lubricant in steering
coupler7. Replace steering coupler
PRE-WHEEL ALIGNMENT INSPECTION
Before any attempt is made to change or correct
the wheel alignment factors. The following part
inspection and the necessary corrections should be
made to those parts which influence the steering of
the vehicle.
(1) Check and inflate all tires to recommended
pressure. All tires should be the same size and in
good condition and have approximately the same
wear. Note the type of tread wear which will aid in
diagnosing, see Wheels and Tires, Group 22.
(2) Check front wheel and tire assembly for radial
runout.
(3) Inspect lower ball joints and all steering link-
age for looseness.
(4) Check for broken or sagged front and rear
springs.(5) Check vehicle ride height to verify it is within
specifications.
(6) AlignmentMUSTonly be checked after the
vehicle has the following areas inspected and or
adjusted. Recommended tire pressures, full tank of
fuel, no passenger or luggage compartment load and
is on a level floor or a properly calibrated alignment
rack.
SERVICE PROCEDURES
WHEEL ALIGNMENT CHECK AND ADJUSTMENT
PROCEDURE
CASTER AND CAMBER
Front suspension Caster and Camber settings on
this vehicle are determined at the time the vehicle is
designed. This is done by determining the precise
2 - 4 SUSPENSIONNS
DIAGNOSIS AND TESTING (Continued)

Mc PHERSON STRUT ASSEMBLY
The front suspension of the vehicle is supported by
coil springs positioned around the strut assembly.
The springs are contained between an upper seat,
located just below the top strut mount assembly and
a lower spring seat on the strut fluid reservoir.
The top of each strut assembly is bolted to the
upper fender reinforcement (strut tower) through a
rubber isolated mount.
The bottom of the strut assembly attaches to the
steering knuckle with two through bolts. Caster is a
fixed setting on all vehicles and is not adjustable
when an alignment is performed. In the event the
camber setting on a vehicle requires adjustment, a
service strut is available which will provide a method
by which the camber can be adjusted.
The strut assemblies on this vehicle are inter-con-
nected by the front stabilizer bar through 2 link
assemblies attaching the struts to the stabilizer bar.
STEERING KNUCKLE
The steering knuckle (Fig. 1) is a single casting
with legs machined for attachment of the strut
damper, steering linkage, disc brake caliper, and
lower control arm ball joint. The steering knuckle
also has the front hub/bearing assembly mounted to
it. The hub is positioned through the bearing and
knuckle, with the constant velocity stub shaft splined
through the hub.
LOWER CONTROL ARM
The lower control arm is an iron casting. The lower
control arm is mounted to and isolated from the body
of the vehicle using 2 types of rubber bushings. The
front lower control arm bushing is the spool type and
is pressed into the lower control arm, while the rear
uses a bushing that is pushed over a stem on the
lower control arm. The front and rear of the lower
control arm is mounted to the cast crossmemberusing a pivot bolt through the center of the front
pivot bushing, and a retainer which traps the rear
bushing in the crossmember.
The ball joint is pressed into the control arm and
has a non-tapered stud with a notch for clamp bolt
clearance. The stud is clamped and locked into the
steering knuckle leg with a clamp bolt.
The ball joint is lubricated for the life of the vehi-
cle and does not require any periodic lubrication.
STABILIZER BAR
The stabilizer bar interconnects both Mc Pherson
strut assemblies of the vehicle and is attached
through rubber isolator bushings to the front suspen-
sion cradle
Jounce and rebound movements affecting one
wheel are partially transmitted to the opposite wheel
to stabilize body roll.
Attachment of the stabilizer bar to the front sus-
pension cradle is through 2 rubber-isolator bushings
and bushing retainers. The stabilizer bar to Mc Pher-
son strut assembly attachment is done utilizing a
sway bar attaching link. All parts of the stabilizer
bar are serviceable, and the stabilizer bar to cross-
member bushings are split for easy removal and
installation. The split in the stabilizer bar to cross-
member bushing should be positioned toward the
rear of the vehicle, with the square corner down
toward the ground, when the stabilizer bar is
installed in the vehicle.
STABILIZER BAR ATTACHING LINK
The stabilizer bar attaching links are used to
attach each end of the stabilizer bar to the front
strut assemblies. This reduces the fore-and-aft rate of
the stabilizer bar from the rest of the vehicle's front
suspension.
HUB AND BEARING ASSEMBLY
The Unit III Front Hub and Bearing Assembly is
used on all front wheel drive vans.
All hub and bearing assemblies mount to the steer-
ing knuckle the same way, but very by the wheel size
on the vehicle. Vehicles equipped with 14 inch wheels
have a 4 inch wheel mounting stud pattern. Vehicles
equipped with 15 inch wheels have a 4 1/2 inch
wheel mounting stud pattern. If a hub and bearing
assembly needs to be replaced, be sure that the
replacement assembly has the same size wheel
mounting stud pattern as the original part.
This unit is serviced only as a complete assembly.
It is mounted to the steering knuckle by four mount-
ing bolts that are removed from the rear of the steer-
ing knuckle.
Fig. 1 Front Steering Knuckle
2 - 10 SUSPENSIONNS
DESCRIPTION AND OPERATION (Continued)

(3) Install the rear brake drum on the hub and
bearing assembly.
(4) Install wheel and tire assembly on vehicle.
Tighten the wheel mounting stud nuts in proper
sequence until all nuts are torqued to half specifica-
tion. Then repeat the tightening sequence to the full
specified torque of 129 N´m (95 ft. lbs.).
(5) Lower vehicle to the ground.
DISASSEMBLY AND ASSEMBLY
Mc PHERSON STRUT
DISASSEMBLY
The Mc Pherson Strut must be remove from the
vehicle for it to be disassembled and assembled.
Refer to Mc Pherson Strut in the Removal And
Installation Section in this group of the service man-
ual for the required procedure to remove and install
the Mc Pherson Strut.
(1) Clamp strut assembly in vise, with strut in a
vertical position.Do not clamp reservoir of strut
assembly in vise, only clamp strut assembly
using strut clevis bracket (Fig. 68).
(2) Mark coil spring and strut assembly right or
left, according to which side of vehicle strut was
removed from, and which strut coil spring was
removed from.
WARNING: DO NOT REMOVE STRUT ROD NUT,
BEFORE STRUT ASSEMBLY COIL SPRING IS COM-
PRESSED, REMOVING SPRING TENSION FROM
UPPER SPRING SEAT AND BEARING ASSEMBLY.
WARNING: WHEN COMPRESSING COIL SPRING
FOR REMOVAL FROM STRUT ASSEMBLY, THE
UPPER SPRING SEAT AND SECOND COIL OF THECOIL SPRING MUST BE CAPTURED BY THE JAWS
OF THE COIL SPRING COMPRESSOR (Fig. 69).
(3) Compress strut coil spring, using Pentastar
Service Equipment Spring Compressor, 7522A (Fig.
69). Be sure the top and bottom attachment shoe
selected, (Fig. 69) properly fit the coil spring.
(4) Install Socket, Strut Nut, Special Tool 6864 on
the strut shaft retaining nut (Fig. 70). Then install a
10 mm socket on the hex of the strut shaft (Fig. 70).
While holding strut shaft from turning, remove nut
from strut shaft.
(5) Remove the upper mount (Fig. 71) from the
strut shaft and coil spring upper seat.
(6) Release the coil spring from the spring com-
pressor. Remove spring compressor from coil spring
(Fig. 72).
(7) Remove the coil spring upper seat and pivot
bearing (Fig. 72) as an assembly from the coil spring.
Remove the coil spring from the strut.Mark left
Fig. 67 Installing Wheel Stud Into Hub And BearingFig. 68 Strut Assembly Correctly Installed In Vise
Fig. 69 Compressing Strut Assembly Coil Spring
2 - 30 SUSPENSIONNS
REMOVAL AND INSTALLATION (Continued)

BASE BRAKE SYSTEM
INDEX
page page
DESCRIPTION AND OPERATION
CHASSIS TUBES AND HOSES.............. 7
FRONT DISC BRAKE SYSTEM.............. 4
HUB/BEARING REAR WHEEL............... 9
MASTER CYLINDER...................... 7
PARKING BRAKE SYSTEM OPERATION....... 5
POWER BRAKE VACUUM BOOSTER
OPERATION........................... 8
PROPORTIONING VALVES................. 5
REAR DISC BRAKES...................... 5
REAR DRUM BRAKES..................... 5
RED BRAKE WARNING LAMP OPERATION..... 8
STOP LAMP SWITCH...................... 9
DIAGNOSIS AND TESTING
ADJUSTER REAR DRUM BRAKE
(AUTOMATIC)......................... 14
BRAKE FLUID CONTAMINATION............ 19
BRAKE ROTOR......................... 14
BRAKE SYSTEM BASIC DIAGNOSIS GUIDE.... 9
BRAKE SYSTEM DIAGNOSIS CHARTS....... 10
PROPORTIONING VALVES................ 16
RED BRAKE WARNING LAMP TEST......... 19
STOP LAMP SWITCH TEST PROCEDURE..... 19
TRACTION CONTROL LAMP TEST.......... 19
SERVICE PROCEDURES
BLEEDING BASE BRAKE
HYDRAULIC SYSTEM................... 20
BRAKE DRUM MACHINING................ 24
BRAKE TUBE REPAIR PROCEDURE......... 24
MASTER CYLINDER BLEEDING
PROCEDURE......................... 22
MASTER CYLINDER FLUID LEVEL CHECK.... 20
PARK BRAKE AUTO ADJUSTER
MECHANISM RELEASE................. 26
ROTOR MACHINING (FRONT/REAR)......... 22
REMOVAL AND INSTALLATION
BRAKE SUPPORT PLATE (REAR DRUM
BRAKES)............................ 37
FRONT DISC BRAKE CALIPER............. 27
FRONT DISC BRAKE PADS................ 30
FRONT PARK BRAKE CABLE.............. 65
HUB/BEARING.......................... 40
HYDRAULIC BRAKE TUBES AND HOSES..... 58
INTERMEDIATE PARK BRAKE CABLE....... 66
JUNCTION BLOCK....................... 55
LEFT REAR PARK BRAKE CABLE........... 67
MASTER CYLINDER..................... 44
PARK BRAKE PEDAL MECHANISM.......... 58PARK BRAKE SHOES (WITH REAR DISC
BRAKES)............................ 60
PROPORTIONING VALVE (W/ABS BRAKES) . . . 56
PROPORTIONING VALVE
(W/O ABS BRAKES).................... 57
REAR BRAKE DRUM..................... 33
REAR BRAKE WHEEL CYLINDER........... 39
REAR DISC BRAKE CALIPER.............. 28
REAR DISC BRAKE SHOES................ 31
REAR DRUM BRAKE SHOES............... 34
RIGHT REAR PARK BRAKE CABLE......... 66
STOP LAMP SWITCH..................... 69
VACUUM BOOSTER 2.4 LITER ENGINE...... 47
VACUUM BOOSTER 3.0 LITER ENGINE...... 49
VACUUM BOOSTER 3.3/3.8 LITER ENGINE.... 52
WHEEL AND TIRE INSTALLATION........... 27
DISASSEMBLY AND ASSEMBLY
FRONT DISC BRAKE CALIPER............. 71
MASTER CYLINDER BRAKE FLUID LEVEL
SWITCH............................. 71
MASTER CYLINDER FLUID RESERVOIR
FILL TUBE............................ 71
MASTER CYLINDER FLUID RESERVOIR...... 70
MASTER CYLINDER TO POWER BRAKE
BOOSTER VACUUM SEAL............... 69
WHEEL CYLINDER REAR DRUM BRAKE...... 76
CLEANING AND INSPECTION
BRAKE HOSE AND BRAKE LINES
INSPECTION.......................... 78
FRONT DISC BRAKE PAD LINING
INSPECTION.......................... 76
REAR DISC BRAKES..................... 76
REAR DRUM BRAKE SHOE LINING
INSPECTION.......................... 77
REAR DRUM BRAKE WHEEL CYLINDER...... 78
REAR WHEEL HUB AND BEARING
ASSEMBLY........................... 78
ADJUSTMENTS
PARK BRAKE CABLE ADJUSTMENT......... 81
PARK BRAKE SHOES (WITH REAR DISC
BRAKES)............................ 79
PROPORTIONING VALVE
(HEIGHT SENSING).................... 81
REAR DRUM BRAKE SHOE ADJUSTMENT.... 79
STOP LAMP SWITCH..................... 78
SPECIFICATIONS
BRAKE ACTUATION SYSTEM.............. 83
BRAKE FASTENER TORQUE
SPECIFICATIONS...................... 83
NSBRAKES 5 - 3

The caliper is a one piece casting with the inboard
side containing a single piston cylinder bore.
The phenolic piston is 60 mm (2.36 inch) in diam-
eter.
A square cut rubber piston seal is located in a
machined groove in the cylinder bore. It provides a
hydraulic seal between the piston and the cylinder
wall (Fig. 4).
The molded rubber dust boot mounts in a counter
bore of the cylinder bore opening and in a groove
which is machined in the outer surface of the piston
(Fig. 4). This prevents contamination of the piston
and the bore area.
As lining wears, reservoir level will go down. If
fluid has been added, reservoir overflow may occur
when the piston is pushed back into the new lining
position. Overflowing can be avoided by removing a
small amount of fluid from the master cylinder res-
ervoir.
REAR DRUM BRAKES
The rear wheel drum brakes are a two shoe, inter-
nal expanding type with an automatic adjuster screw.
The automatic adjuster screw is actuated each time
the brakes are applied. The automatic adjuster screw
is located directly below the wheel cylinder.
REAR DISC BRAKES
The rear disc brakes are similar to front disc
brakes, however, there are several distinctive fea-
tures that require different service procedures. The
single piston, floating caliper rear disc brake system
includes a hub and bearing assembly, adapter, rotor,
caliper, and brake shoes. The parking brake system
on vehicles equipped with rear disc brakes, consists
of a small duo-servo drum brake mounted to the cal-
iper adapter. The drum brake shoes expand out
against a braking surface (hat section) on the inside
area of the rotor.
This vehicle is equipped with a caliper having a 42
mm (1.65 in.) piston and uses a 15 inch solid non-
vented rotor.The disc brake caliper floats on rubber bushings
using threaded guide pin bolts which are attached to
the back side of the adapter.
The adapter and rotor shield are mounted to the
rear axle. The adapter is used to mount the brake
shoes and actuating cables for the parking brake sys-
tem. The adapter is also used to mount the rear cal-
iper. The adapter has two machined abutments
which are used to position and align the caliper and
brake shoes for movement inboard and outboard (Fig.
5).
PARKING BRAKE SYSTEM OPERATION
The rear wheel service brakes also act as parking
brakes. The brake shoes are mechanically operated
by an internal lever and strut connected to a flexible
steel cable. The rear cables and intermediate cable
are connected to the front cable by an equalizer. The
front cable extends to the parking brake foot pedal
assembly.
PROPORTIONING VALVES
FIXED PROPORTIONING VALVE
The hydraulic brake system on all vehicles is diag-
onally split. This means that the left front and right
rear brakes are on one hydraulic circuit with the
right front and left rear brakes on the other hydrau-
lic circuit.
On vehicles equipped with ABS brakes, the brake
systems hydraulic control unit (HCU) is mounted to
the front suspension crossmember on the driver's
side of the vehicle. The (HCU) acts as the hydraulic
system junction block, diagonally splitting the brakes
hydraulic system.
All vehicles equipped with ABS brakes use 2 fixed
proportioning valves. The fixed proportioning valves
are mounted in a common bracket on the left frame
rail at the rear of the vehicle (Fig. 6).
Fig. 4 Caliper Piston Seal Function For Automatic
Adjustment
Fig. 5 Rear Disc Brake Components
NSBRAKES 5 - 5
DESCRIPTION AND OPERATION (Continued)

(Fig. 8). The actuator assembly is mounted between
the height sensing proportioning valve and the actua-
tor bracket on the left rear leaf spring (Fig. 8). As the
rear height of the vehicle changes depending on the
load the vehicle is carrying the height change is
transferred to the height sensing proportioning valve.
This change in vehicle height is transferred through
the movement of the left rear leaf spring. As the posi-
tion of the left rear leaf spring changes this move-
ment is transferred through the actuator bracket
(Fig. 8) to the actuator assembly (Fig. 8) and then to
the proportioning valve.
Thus, the height sensing proportioning valve
allows the brake system to maintain the optimal
front to rear brake balance regardless of the vehicle
load condition. Under a light load condition, hydrau-
lic pressure to the rear brakes is minimized. As the
load condition of the vehicle increases, so does the
hydraulic pressure to the rear brakes.
The proportioning valve section of the valve oper-
ates by transmitting full input hydraulic pressure to
the rear brakes up to a certain point, called the split
point. Beyond the split point the proportioning valve
reduces the amount of hydraulic pressure to the rear
brakes according to a certain ratio. Thus, on light
brake applications, approximately equal hydraulic
pressure will be transmitted to the front and rear
brakes. At heavier brake applications, the hydraulic
pressure transmitted to the rear brakes will be lower
then the front brakes. This will prevent premature
rear wheel lock-up and skid.
The height sensing section of the valve thus
changes the split point of the proportioning valve,
based on the rear suspension height of the vehicle.
When the height of the rear suspension is low, the
proportioning valve interprets this as extra load and
the split point of the proportioning valve is raised to
allow more rear braking. When the height of the rear
suspension is high, the proportioning valve interprets
this as a lightly loaded vehicle and the split point of
the proportioning valve is lowered and rear braking
is reduced.
CHASSIS TUBES AND HOSES
The purpose of the chassis brake tubes and flex
hoses is to transfer the pressurized brake fluid devel-
oped by the master cylinder to the wheel brakes of
the vehicle. The chassis tubes are steel with a corro-
sion resistant coating applied to the external surfaces
and the flex hoses are made of reinforced rubber. The
rubber flex hoses allow for the movement of the vehi-
cles suspension.
MASTER CYLINDER
The master cylinder (Fig. 9) consists of the follow-
ing components. The body of the master cylinder isan anodized aluminum casting. It has a machined
bore to accept the master cylinder piston and
threaded ports with seats for the hydraulic brake
line connections. The brake fluid reservoir of the
master cylinder assembly is made of a see through
polypropylene type plastic. A low fluid switch is also
part of the reservoir assembly.
This vehicle uses 3 different master cylinders.
Master cylinder usage depends on what type of brake
system the vehicle is equipped with. If a vehicle is
not equipped with antilock brakes, or is equipped
with antilock brakes without traction control, a con-
ventional compensating port master cylinder is used.
If a vehicle is equipped with antilock brakes with
traction control, a dual center port master cylinder is
used.
The third master cylinder used on this vehicle is
unique to vehicles equipped with four wheel disc
brakes. The master cylinder used for this brake
application has a different bore diameter and stroke
then the master cylinder used for the other available
brake applications.
The master cylinders used on front wheel drive
applications (non four wheel disc brake vehicles)
have a master cylinder piston bore diameter of 23.8
mm. The master cylinder used on the all wheel drive
applications (four wheel disc brake vehicles) have a
master cylinder piston bore diameter of 25.4 mm.
When replacing a master cylinder, be sure to
use the correct master cylinder for the type of
brake system the vehicle is equipped with.
The master cylinder is not a repairable component
and must be replaced if diagnosed to be functioning
improperly
CAUTION: Do not hone the bore of the cylinder as
this will remove the anodized surface from the bore.
The master cylinder primary outlet port supplies
hydraulic pressure to the right front and left rear
Fig. 9 Master Cylinder Assembly
NSBRAKES 5 - 7
DESCRIPTION AND OPERATION (Continued)

brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
POWER BRAKE VACUUM BOOSTER OPERATION
All vehicles use a 270 mm single diaphragm power
brake vacuum booster.
The power brake booster can be identified if
required, by the tag attached to the body of the
booster assembly (Fig. 10). This tag contains the fol-
lowing information: The production part number of
the power booster assembly, the date it was built,
and who was the manufacturer of the power brake
vacuum booster.
NOTE: The power brake booster assembly is not a
repairable component and must be replaced as a
complete assembly if it is found to be faulty in any
way. The check valve located in the power brake
booster (Fig. 10) is not repairable but it can be
replaced as an assembly separate from the power
brake booster.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop vehicle.
The power brake booster is vacuum operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 10) and (Fig. 11).
As the brake pedal is depressed, the power brake
boosters input rod moves forward (Fig. 11). This
opens and closes valves in the power booster, allow-
ing atmospheric pressure to enter on one side of a
diaphragm. Engine vacuum is always present on the
other side. This difference in pressure forces the out-
put rod of the power booster (Fig. 11) out against the
primary piston of the master cylinder. As the pistons
in the master cylinder move forward this creates the
hydraulic pressure in the brake system.The different engine combinations used on this
vehicle require that different vacuum hose routings
to the power brake vacuum booster be used.
All vacuum hoses must be routed from the engine
to the power brake vacuum booster without kinks,
excessively tight bends or potential for damage to the
vacuum hose.
The power brake vacuum booster assembly mounts
on the engine side of the dash panel, and is con-
nected to the brake pedal by the input push rod (Fig.
11). A vacuum line connects the power booster to the
intake manifold. The master cylinder is bolted to the
front of the power brake vacuum booster assembly.
RED BRAKE WARNING LAMP OPERATION
The red Brake warning lamp is located in the
instrument panel cluster and is used to indicate a
low brake fluid condition or that the parking brake is
applied. In addition, the brake warning lamp is
turned on as a bulb check by the ignition switch
every time the ignition switch is turned to the crank
position.
The warning lamp bulb is supplied a 12 volt igni-
tion feed anytime the ignition switch is on. The bulb
is then illuminated by completing the ground circuit
either through the park brake switch, the fluid level
sensor in the master cylinder reservoir, or the igni-
tion switch when it is turned to the crank position.
The Brake Fluid Level sensor is located in the
brake fluid reservoir of the master cylinder assembly.
The purpose of the sensor is to provide the driver
with an early warning that brake fluid level in the
master cylinder fluid reservoir has dropped to below
Fig. 10 Power Brake Booster Identification
Fig. 11 Power Brake Booster Assembly
5 - 8 BRAKESNS
DESCRIPTION AND OPERATION (Continued)

normal. This may indicate:(1)Abnormal loss of
brake fluid in the master cylinder fluid reservoir
resulting from a leak in the hydraulic system.(2)
Brake shoe linings which have worn to a point
requiring replacement.
As the brake fluid drops below the minimum level,
the brake fluid level sensor closes to ground the
brake warning light circuit. This will turn on the red
brake warning light. At this time, master cylinder
fluid reservoir should be checked and filled to the full
mark with DOT 3 brake fluid.If brake fluid level
has dropped below the add line in the master
cylinder fluid reservoir, the entire brake
hydraulic system should be checked for evi-
dence of a leak.
STOP LAMP SWITCH
The stop lamp switch controls operation of the
vehicles stop lamps. Also, if the vehicle is equippedwith speed control, the stop lamp switch will deacti-
vate speed control when the brake pedal is
depressed.
The stop lamp switch controls operation of the
right and left tail, stop and turn signal lamp and
CHMSL lamp, by supplying battery current to these
lamps.
The stop lamp switch controls the lamp operation
by opening and closing the electrical circuit to the
stop lamps.
HUB/BEARING REAR WHEEL
The rear hub and bearing assembly used on this
vehicle is serviceable only as a complete assembly. No
attempt should be made to disassemble a rear hub
and bearing assembly in an effort to repair it.
The rear hub and bearing assembly is attached to
the rear axle using 4 mounting bolts that are remov-
able from the back of the rear hub/bearing.
DIAGNOSIS AND TESTING
BRAKE SYSTEM BASIC DIAGNOSIS GUIDE
SYMPTOMCHART 1
MISC.
COND.CHART 2
WARNING
LIGHTCHART 3
POWER
BRAKESCHART 4
BRAKE
NOISECHART 5
WHEEL
BRAKES
Brake Warning Light On X NO NO
Excessive Pedal Travel 6 X NO O
Pedal Goes To The Floor 6 X
Stop Light On Without Brakes 3
All Brakes Drag 5
Rear Brakes Drag 2 NO NO
Grabby Brakes O X
Spongy Brake Pedal X NO
Premature Rear Brake Lockup 4 NO NO O
Excessive Pedal Effort 1 O
Rough Engine Idle NO O
Brake Chatter (Rough) NO NO X
Surge During Braking NO NO X
Noise During Braking NO NO X
Rattle Or Clunking Noise NO NO X
Pedal Pulsates During Braking NO NO X
Pull To Right Or Left NO NO X
No: Not A Possible Cause X: Most Likely Cause O: Possible Cause
NSBRAKES 5 - 9
DESCRIPTION AND OPERATION (Continued)