service CHRYSLER VOYAGER 2004 Manual PDF

OPERATION - DISC BRAKES (REAR)
The rear disc brakes operate similarly to front disc
brakes, however, there are some features that require
different service procedures.
DIAGNOSIS AND TESTING - DRUM BRAKE
AUTOMATIC ADJUSTER
The rear drum brakes on this vehicle automatically
adjust when required during the normal operation of
the vehicle every time the brakes are applied. Use
the following procedure to test the operation of the
automatic adjuster. Place the vehicle on a hoist with a helper in the
driver's seat to apply the brakes. Remove the access
plug from the adjustment hole in each brake support
plate to provide visual access of the brake adjuster
star wheel. To eliminate the condition where maximum adjust-
ment of the rear brake shoes does not allow the auto-
matic adjuster to operate when tested, back the star
wheel off approximately 30 notches. It will be neces-
sary to hold the adjuster lever away from the star
wheel to permit this adjustment. Have the helper apply the brakes. Upon applica-
tion of the brake pedal, the adjuster lever should
move down, turning the adjuster star wheel. Thus, a
definite rotation of the adjuster star wheel can be
observed if the automatic adjuster is working prop-
erly. If one or more adjusters do not function prop-
erly, the respective drum must be removed for
adjuster servicing.
BRAKE LINES
DESCRIPTION - BRAKE TUBES AND HOSES
The brake tubes are steel with a corrosion-resis-
tant nylon coating applied to the external surfaces.
The flex hoses are made of reinforced rubber with fit-
tings at each end. The primary and secondary brake tubes leading
from the master cylinder to the ABS ICU Hydraulic
Control Unit (HCU) or the non-ABS junction block
have a special flexible section. This flexible section is
required due to cradle movement while the vehicle is
in motion (The ICU and non-ABS junction block are
mounted to the cradle). If replacement of these
lines is necessary, only the original factory
brake line containing the flexible section must
be used .
OPERATION - BRAKE 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 flex hoses are made of rubber to
allow for the movement of the vehicle's suspension.
INSPECTION - BRAKE TUBES AND HOSES
Flexible rubber hose is used at both front brakes
and at the rear axle. Inspection of brake hoses
should be performed whenever the brake system is
serviced and every 7,500 miles or 12 months, which-
ever comes first (every engine oil change). Inspect
hydraulic brake hoses for surface cracking, scuffing,
or worn spots. If the fabric casing of the rubber hose
becomes exposed due to cracks or abrasions in the
rubber hose cover, the hose should be replaced imme-
diately. Eventual deterioration of the hose can take
place with possible burst failure. Faulty installation
can cause twisting, resulting in wheel, tire, or chassis
interference. The brake tubing should be inspected periodically
for evidence of physical damage or contact with mov-
ing or hot components. The flexible brake tube sections used on this vehi-
cle in the primary and secondary tubes from the
master cylinder to the ABS hydraulic control unit
connections must also be inspected. This flexible tub-
ing must be inspected for kinks, fraying and contact
with other components or with the body of the vehi-
cle.
Fig. 10 Caliper Piston Seal Function For Automatic Adjustment
1 - PISTON
2 - CYLINDER BORE
3 - PISTON SEAL BRAKE PRESSURE OFF
4 - CALIPER HOUSING
5 - DUST BOOT
6 - PISTON SEAL BRAKE PRESSURE ON
RS BRAKES5s-13
HYDRAULIC/MECHANICAL (Continued)

specification. Then repeat the tightening sequence to
the full specified torque of 135 N´m (100 ft. lbs.).(8) Lower the vehicle.
(9) Remove the brake pedal depressor (holding)
tool. (10) Bleed the hydraulic brake circuit to the brake
caliper. (Refer t o 5 - BRAKES - STANDARD PROCE-
DURE) (11) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake shoe linings.
DISC BRAKE CALIPER
ADAPTER
REMOVAL - FRONT DISC BRAKE CALIPER
ADAPTER
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE) (2) Remove front wheel and tire assembly, disc
brake caliper and brake shoes. (Refer t o 5 - BRAKES/
HYDRAULIC/MECHANICAL/BRAKE PADS/SHOES
- REMOVAL) (3) Remove two bolts fastening adapter to steering
knuckle, then remove disc brake caliper adapter.
INSTALLATION - FRONT DISC BRAKE CALIPER
ADAPTER
(1) Place adapter over brake rotor and align
adapter mounting holes to knuckle.
CAUTION: Adapter mounting bolts have a special
Dacromet Tcoating applied to resist corrosion. If
mounting bolts need to be replaced, use only
Mopar Treplacement parts.
(2) Install adapter mounting bolts and tighten to
169 N´m (125 ft. lbs.) torque. (3) Install brake shoes, disc brake caliper and
wheel and tire assembly. (Refer t o 5 - BRAKES/HY-
DRAULIC/MECHANICAL/BRAKE PADS/SHOES -
INSTALLATION) (4) Lower vehicle.
(5) Pump the brake pedal several times to set the
pads to the brake rotor. (6) Check and adjust brake fluid level as neces-
sary.
DISC BRAKE CALIPER GUIDE
PINS
REMOVAL - DISC BRAKE CALIPER GUIDE PINS
(TRW BRAKES)
(1) Raise the vehicle. Refer to HOISTING in
LUBRICATION AND MAINTENANCE. (2) Remove the front tire and wheel assembly.
(3) Remove the two brake caliper guide pin bolts
(Fig. 42).
(4) Remove the disc brake caliper from the disc
brake caliper adapter and hang it out of the way
using wire or a bungee cord. Use care not to overex-
tend the brake hose when doing this. (5) Remove the guide pins and boots from the
adapter as shown (Fig. 43).
INSTALLATION - DISC BRAKE CALIPER GUIDE
PINS (TRW BRAKES)
(1) Lubricate the guide pins and inside the boots
with the packet supplied with the service kit, Syth-
eso GLK-1 lubricant or equivalent. (2) Install the guide pins and boots in the adapter
as shown (Fig. 43). The boots have grooves built into
their inner lips to fit onto the pins and adapter.
CAUTION: Use care when installing the caliper onto
the disc brake adapter to avoid damaging the boots
on the caliper guide pins.
Fig. 42 Brake Caliper Mounting
1 - BRAKE HOSE
2 - ADAPTER MOUNTING BOLTS
3 - BANJO BOLT
4 - CALIPER GUIDE PIN BOLTS
5s - 30 BRAKESRS
DISC BRAKE CALIPER - REAR (Continued)

(3) Install the disc brake caliper over the brake
shoes on the brake caliper adapter. (4) Align the caliper guide pin bolt holes with the
guide pins. Install the caliper guide pin bolts and
tighten them to a torque of 35 N´m (26 ft. lbs.) (Fig.
42). (5) Install the tire and wheel assembly. Tighten
the wheel mounting nuts to a torque of 135 N´m (100
ft. lbs.). (6) Lower the vehicle.
(7) Pump the brake pedal several times before
moving the vehicle to set the shoes to the brake
rotor.
DRUM
REMOVAL
(1) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE). (2) Remove the tire and wheel assembly from the
vehicle (3) Remove the rear brake shoe adjusting hole
cover plug. (4) Insert a thin screwdriver into brake adjusting
hole and hold adjusting lever away from notches of
adjusting screw star wheel. (5) Insert another thin screwdriver into brake
adjusting hole and engage notches of brake adjusting
screw star wheel. Release brake adjustment by pry-
ing upward with adjusting tool. (6) Remove rear brake drum from rear hub/bear-
ing assembly. NOTE: It may be necessary to insert M8 X 1.25 MM
bolts into the two removal holes on the drum to
force the drum off the hub.
INSTALLATION
(1) Adjust brake shoe assemblies so as not to inter-
fere with brake drum installation. (2) Install the rear brake drums on the hubs.
(3)
Adjust drum brake shoes as necessary per proce-
dure found in the Adjustment section of this service
manual group (Refer t o 5 - BRAKES/HYDRAULIC/
MECHANICAL/DRUM - ADJUSTMENTS).
(4) Install wheel and tire assembly.
(5) Tighten the wheel mounting stud nuts in
proper sequence until all nuts are torqued to half
specification. Then repeat the tightening sequence to
the full specified torque of 135 N´m (100 ft. lbs.). (6) Lower the vehicle.
FLUID
DIAGNOSIS AND TESTING - BRAKE FLUID
CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts. Swollen rubber parts indicate the presence of
petroleum in the brake fluid. To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid. If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brake hydraulic unit and all hydraulic fluid
hoses.
STANDARD PROCEDURE - BRAKE FLUID
LEVEL CHECKING
Check master cylinder reservoir fluid level a mini-
mum of twice annually. Fluid reservoirs are marked with the words FULL
and ADD to indicate proper brake fluid fill level of
the master cylinder. If necessary, add brake fluid to bring the level to
the bottom of the FULL mark on the side of the mas-
ter cylinder fluid reservoir. Use only Mopar tbrake fluid or equivalent from a
sealed container. Brake fluid must conform to DOT 3
specifications (DOT 4 or DOT 4+ are acceptable). DO NOT use brake fluid with a lower boiling
point, as brake failure could result during prolonged
hard braking.
Fig. 43 Guide Pins And Boots
1 - PINS
2 - BOOTS
RS BRAKES5s-31
DISC BRAKE CALIPER GUIDE PINS (Continued)

(3) Install two upper mounting bolts attaching
pedals assembly to steering column support bracket
on dash panel. Do not fully tighten at this time.
(4) Install four nuts attaching pedals assembly and
power brake booster to dash panel (Fig. 61). (5) Tighten four booster mounting nuts and two
upper mounting bolts to 28 N´m (21 ft. lbs.) torque. (6) Route pedal adjuster cable up and over right
side of pedals assembly and steering column bracket, then down through hole in steering column bracket
as shown (Fig. 60). Attach end of cable to gear box.
(7) Place adjuster cable through loop on right side
of steering column bracket as shown (Fig. 60). (8) Install booster input rod onto brake pedal pin
and install a NEW retaining clip. (9) Connect wiring connector connecting vehicle
wiring harness to pedal wiring harness (Fig. 58). (10) Connect routing clips retaining vehicle wiring
harness to pedal wiring harness (Fig. 58). (11) Install brake lamp switch bracket on pedals
assembly. Tighten mounting nuts to 6 N´m (50 in.
lbs.) torque. (12) Install dash seal silencer shell over steering
column intermediate shaft and fasten in place (Fig.
57). (13) Install steering column onto lower mounting
studs with nuts started, then install column onto
upper mounting studs and install two upper mount-
ing nuts. Tighten upper, then lower mounting nuts to
12 N´m (105 in. lbs.) torque. (14) Install column shaft coupling onto intermedi-
ate shaft and install pinch bolt. Make sure rounded
side of intermediate shaft is matched to the curva-
ture of the coupling. Tighten pinch bolt to 28 N´m
(250 in. lbs.) torque. (15) Remove retainer holding steering wheel in
place on steering column. (16) Attach shift cable to bracket on column.
(17) Connect shift cable end to shift lever mecha-
nism pin (Fig. 55). (18) If equipped, connect PRNDL cable to end of
shift lever mechanism pin and column bracket (Fig.
55). (19) Connect column wiring harness connectors (as
equipped) to SKIM, BTSI solenoid, ignition switch,
multi-function switch, and clockspring. (20) Install lower and upper steering column
shrouds. (Refer to 19 - STEERING/COLUMN/
LOWER SHROUD - INSTALLATION)
CAUTION: Do not reuse the original brake lamp
switch. The switch can only be adjusted once. That
is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for some service, a new switch must be
installed and adjusted.
(21) Install and adjust NEW brake lamp switch.
(Refer t o 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/BRAKE LAMP SWITCH - INSTALLA-
TION) (22) Install instrument panel lower left reinforce-
ment (Fig. 54). (23) Attach hood release to lower left reinforce-
ment.
Fig. 60 Drive Cable Routing
1 - ADJUSTER CABLE
2 - ROUTING LOOP
3 - CABLE ATTACHMENT AT MOTOR
4 - GEAR DRIVE
5 - CABLE ATTACHMENT AT GEAR BOX
6 - STEERING COLUMN BRACKET
Fig. 61 Booster Mounting (Typical)
1 - DASH BRACKET
2 - POWER BRAKE BOOSTER
3 - BRAKE PEDAL ASSEMBLY
RS BRAKES5s-41
PEDALS - ADJUSTABLE (Continued)

INSTALLATION
(1) Lubricate both ends of the torque shaft with
MS-4517 Lubricant or equivalent and install the
torque shaft from the left side reversing the removal
procedure. (2) Install the brake booster bracket on the left
end of the shaft. (3) Install the retaining nut for the brake booster
bracket in the engine compartment. Tighten the
mounting nut to a torque of 29 N´m (250 in. lbs.). (4) Install the four brake booster retaining nuts
inside the passenger compartment. Tighten the
mounting nuts to a torque of 29 N´m (250 in. lbs.). (5) Using lubriplate, or equivalent, coat the sur-
face of the brake pedal torque shaft pin where it con-
tacts the booster input rod. Also coat the surface of
the brake pedal torque shaft pin where it contacts
the brake pedal link.
CAUTION: When installing the power brake booster
input rod on the brake pedal torque shaft pin, do
not reuse the old retaining clip.
(6) Install booster input rod on brake pedal torque
shaft pin and install a NEW retaining clip (Fig. 62).
CAUTION: When installing the brake pedal link on
the brake pedal torque shaft pin, do not reuse the
old retaining clip.
(7) Connect the brake pedal link to the torque
shaft. Install a NEW retaining clip at the torque
shaft end of the brake pedal-to-torque shaft link. (8) Install the HVAC housing. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION) (9) Install the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION)
CAUTION: Do not reuse the original brake lamp
switch. The switch can only be adjusted once. That
is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for some service, a new switch must be
installed and adjusted.
(10) Remove and replace the brake lamp switch
with a NEW switch. (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - INSTALLATION) (11) Road test vehicle to ensure proper operation of
the brakes.
POWER BRAKE BOOSTER
DESCRIPTION
The power brake booster mounts on the engine
compartment side of the dash panel. It is connected
to the brake pedal by the input (push) rod (Fig. 64).
The master cylinder is bolted to the front of the
booster. A vacuum line connects the power brake
booster to the intake manifold.
All Left-Hand-Drive (LHD) vehicles use a 270 mm
single diaphragm vacuum power brake booster. All
Right-Hand-Drive (RHD) vehicles use a 225/200 mm
tandem diaphragm vacuum power brake booster. Vehicles equipped with Disc/Disc brakes use a dif-
ferent power brake booster than vehicles equipped
with Disc/Drum brakes. Differences between the two
are internal. Service is the same for all boosters. The power brake booster can be identified by the
tag attached to the body of the booster (Fig. 65). This
tag contains the production part number, the date it
was built, and who the manufacturer of the power
brake booster is.
Fig. 64 Power Brake Booster (Typical)
1 - VACUUM CHECK VALVE
2 - POWER BRAKE BOOSTER ASSEMBLY
3 - INPUT ROD
4 - POWER BOOSTER ASSEMBLY TO DASH PANEL MOUNTING
STUDS (4)
5 - MASTER CYLINDER MOUNTING STUDS (2)
6 - OUTPUT ROD
RS BRAKES5s-43
PEDAL TORQUE SHAFT - RHD (Continued)

(16) Disconnect vacuum hose from check valve
located on vacuum booster. DO NOT REMOVE
CHECK VALVE FROM POWER BRAKE
BOOSTER. (17) Inside vehicle, remove silencer panel under
instrument panel below steering column. (18) Locate the booster input rod to brake pedal
connection under the instrument panel. Position a
small screwdriver between the center tang on the
power brake booster input rod to brake pedal pin
retaining clip (Fig. 68). (19) Rotate screwdriver enough to allow retaining
clip center tang to pass over end of brake pedal pin.
Then pull retaining clip off brake pedal pin. Discard
retaining clip. It is not to be reused. Replace
only with a new retaining clip when assem-
bling. (20) Slide booster input rod off pedal pin.
(21) Remove the four nuts attaching power brake
booster to dash panel (Fig. 69).
(22) Slide power brake booster forward and remove
through engine compartment (Fig. 70).
CAUTION: Do not attempt to disassemble the power
brake vacuum booster. It is serviced ONLY as a
complete assembly.
Fig. 67 Master Cylinder Mounting
1 - MASTER CYLINDER MOUNTING NUTS
2 - MASTER CYLINDER
3 - SECONDARY TUBE NUT AT ICU
4 - PRIMARY TUBE NUT AT ICU
Fig. 68 Vacuum Booster Input Rod Retaining Pin
1 - BRAKE PEDAL
2 - INPUT ROD
3 - SCREWDRIVER
4 - RETAINING CLIP
5 - BRAKE PEDAL PIN
Fig. 69 Booster Mounting
1 - DASH BRACKET
2 - POWER BRAKE BOOSTER
3 - BRAKE PEDAL ASSEMBLY
Fig. 70 Booster Removal/Installation
5s - 46 BRAKESRS
POWER BRAKE BOOSTER (Continued)

(15) Under the instrument panel, remove booster
input rod trim cover. (16) Locate the booster input rod to brake pedal
torque shaft connection under the instrument panel.
Position a small screwdriver between the center tang
on the retaining clip (Fig. 73).
(17) Rotate screwdriver enough to allow retaining
clip center tang to pass over end of brake pedal pin.
Then pull retaining clip off brake pedal torque shaft
pin. Discard retaining clip. It is not to be
reused. Replace only with a new retaining clip
when assembling. (18) Remove booster input rod from pedal torque
shaft pin. (19) Remove the three easily accessed mounting
nuts attaching power brake booster to dash panel
and loosen fourth (Fig. 74). As fourth nut is loosened,
push the booster forward periodically until the nut
can be completely removed. (20) Slide power brake booster forward and remove
through engine compartment (Fig. 75).
CAUTION: Do not attempt to disassemble the power
brake vacuum booster. It is serviced ONLY as a
complete assembly.
Fig. 73 Booster Input Rod Pin Retaining Clip (Typical)
1 - BRAKE PEDAL
2 - INPUT ROD
3 - SCREWDRIVER
4 - RETAINING CLIP
5 - BRAKE PEDAL PIN
Fig. 74 Booster, Torque Shaft And Pedal Mounting
1 - PEDAL MOUNTING NUT
2 - BRAKE PEDAL ASSEMBLY
3 - PEDAL MOUNTING NUT
4 - PEDAL TORQUE SHAFT
5 - BOOSTER MOUNTING NUT
6 - BOOSTER BRACKET
7 - POWER BRAKE BOOSTER
8 - BOOSTER BRACKET MOUNTING NUT
Fig. 75 RHD Booster Removal/Installation
1 - POWER BRAKE BOOSTER
2 - MASTER CYLINDER
5s - 48 BRAKESRS
POWER BRAKE BOOSTER (Continued)

INSTALLATION
INSTALLATION - LHD
(1) Position power brake booster on dash panel
using the reverse procedure of its removal (Fig. 70).
It may be necessary to push in on booster input rod
as it is guided through the dash panel. (2) Install the four nuts mounting the booster to
the dash panel (Fig. 69). Tighten the mounting nuts
to a torque of 29 N´m (250 in. lbs.). (3) Using lubriplate, or equivalent, coat the sur-
face of the brake pedal pin where it contacts the
booster input rod.
CAUTION: When installing the brake pedal pin on
the power brake booster input rod, do not re-use
the old retaining clip.
(4) Install booster input rod on brake pedal pin
and install a NEW retaining clip (Fig. 76).
CAUTION: Do not reuse the original brake lamp
switch. The switch can only be adjusted once. That
is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for some service, a new switch must be
installed and adjusted.
(5) Remove and replace the brake lamp switch
with a NEW switch. (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - INSTALLATION) (6) Install the silencer panel below the steering
column. (7) Connect vacuum hose to check valve on power
brake booster.
CAUTION: The master cylinder (and its rear seal) is
used to create the seal for holding vacuum in the
vacuum booster. The vacuum seal on the master
cylinder MUST be replaced with a NEW seal when-
ever the master cylinder is removed from the vac-
uum booster.
CAUTION: When removing the vacuum seal from
the master cylinder do not use a sharp tool.
(8) Using a soft tool such as a trim stick, remove
the vacuum seal from the master cylinder mounting
flange. (9) Install a NEW vacuum seal on rear mounting
flange of the master cylinder (Fig. 77).
(10) Position master cylinder on studs of booster,
aligning push rod on booster with master cylinder
piston. (11) Install the two nuts mounting the master cyl-
inder to the booster (Fig. 67). Tighten both mounting
nuts to a torque of 25 N´m (225 in. lbs.). (12) Connect wiring harness connector to brake
fluid level switch in the master cylinder fluid reser-
voir (Fig. 66). (13) Connect primary and secondary brake tubes
to ABS ICU or non-ABS junction block (Fig. 67).
Tighten the tube nuts to 17 N´m (145 in lbs.). (14) Install wiper module (unit). (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WIPER MOD-
ULE - INSTALLATION) (15) If equipped with speed control, install speed
control servo and connect wiring connector. Tighten
Fig. 76 Retaining Pin Installed On Brake Pedal Pin
1 - BRAKE PEDAL
2 - RETAINING CLIP
3 - BOOSTER INPUT ROD
Fig. 77 Vacuum Seal (Typical)
1 - MASTER CYLINDER ASSEMBLY
2 - VACUUM SEAL
RS BRAKES5s-49
POWER BRAKE BOOSTER (Continued)

(11) Connect wiring harness connector to brake
fluid level switch in the master cylinder fluid reser-
voir (Fig. 71). (12) If the vehicle is equipped with the 2.5L diesel
engine, install the coolant recovery pressure con-
tainer and bracket. (Refer t o 7 - COOLING/ENGINE/
COOLANT RECOVERY PRESS CONTAINER -
INSTALLATION) (13) If equipped with speed control, install speed
control servo and connect wiring connector. Tighten
the mounting nuts to a torque of 14 N´m (124 in.
lbs.). (14) Install the battery tray. Install the two nuts
and one bolt attaching the battery tray to the vehicle.
Tighten the bolt and nuts to a torque of 14 N´m (124
in. lbs.). (15) If vehicle is equipped with speed control, con-
nect the servo vacuum hose to the vacuum tank on
the battery tray. (16) Install the battery, clamp and mounting nut.
(17) Install the positive battery cable on the bat-
tery. (18) Install the negative battery cable on the bat-
tery. (19) Install the battery thermal guard shield.
CAUTION: Do not reuse the original brake lamp
switch. The switch can only be adjusted once. That
is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for some service, a new switch must be
installed and adjusted. (20) Remove and replace the brake lamp switch
with a NEW switch. (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer t o 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - INSTALLATION) (21) Bleed the base brakes as necessary. (Refer to
5 - BRAKES - STANDARD PROCEDURE) (22) Road test vehicle to ensure proper operation
of the brakes.
PROPORTIONING VALVE
DESCRIPTION - PROPORTIONING VALVE
(HEIGHT SENSING)
NOTE: Only vehicles without antilock brakes (ABS)
have a proportioning valve. Vehicles with ABS uti-
lize electronic brake distribution which is controlled
through the ABS integrated control unit.
Vehicles not equipped with ABS use a height sens-
ing proportioning valve. It is mounted to the body of the vehicle above the rear axle (Fig. 80). It has an
actuator lever that attaches to the rear axle and
moves with the axle to help the valve sense the vehi-
cle height.
CAUTION: The height sensing proportioning valve
is not adjustable. No attempt should be made to
adjust it. It is replaced as a complete assembly.
CAUTION: The use of after-market load leveling or
load capacity increasing devices on this vehicle are
prohibited. Using air shock absorbers or helper
springs on this vehicle will cause the height sens-
ing proportioning valve to inappropriately reduce
the hydraulic pressure to the rear brakes. This inap-
propriate reduction in hydraulic pressure potentially
could result in increased stopping distance of the
vehicle.
OPERATION - PROPORTIONING VALVE
(HEIGHT SENSING)
Vehicles not equipped with ABS use a height sens-
ing proportioning valve. The height sensing proportioning valve operates
similarly to a standard proportioning valve in the fol-
lowing way. As hydraulic pressure is applied to the
valve, full input hydraulic pressure is supplied to the
rear brakes up to a certain pressure 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 given ratio. Thus, on
light brake applications, approximately equal
hydraulic pressure will be transmitted to both the
front and rear brakes. Upon heavier brake applica-
tions, the hydraulic pressure transmitted to the rear
Fig. 80 HEIGHT SENSING PROPORTIONING VALVE
1 - PROPORTIONING VALVE
2 - ACTUATOR LEVER
3 - AXLE BRACKET
4 - REAR AXLE
RS BRAKES5s-51
POWER BRAKE BOOSTER (Continued)

(6) Road test the vehicle to verify proper operation
of the brake system.
ROTOR
DIAGNOSIS AND TESTING - BRAKE ROTOR
Any servicing of the rotor requires extreme care to
maintain the rotor within service tolerances to
ensure proper brake action. Excessive runout or wobble in a rotor can increase
pedal travel due to piston knock-back. This increases
guide pin sleeve wear due to the tendency of the cal-
iper to follow the rotor wobble. When diagnosing a brake noise or pulsation, the
machined disc braking surface should be checked and
inspected.
BRAKING SURFACE INSPECTION
Light braking surface scoring and wear is accept-
able. If heavy scoring or warping is evident, the rotor
must be refaced or replaced. (Refer t o 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTORS - STAN-
DARD PROCEDURE). Excessive wear and scoring of the rotor can cause
improper lining contact on the rotor's braking sur-
face. If the ridges on the rotor are not removed before
new brake shoes are installed, improper wear of the
shoes will result. If a vehicle has not been driven for a period of
time, the rotor's braking surface will rust in the
areas not covered by the brake shoes at that time.
Once the vehicle is driven, noise and chatter from
the disc brakes can result when the brakes are
applied. Some discoloration or wear of the rotor surface is
normal and does not require resurfacing when lin-
ings are replaced. If cracks or burned spots are evi-
dent, the rotor must be replaced.
ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake
shoe contact surface. Replace the rotor if it is worn
below minimum thickness or if machining the rotor
will cause its thickness to fall below specifications.
CAUTION: Do not machine the rotor if it will cause
the rotor to fall below minimum thickness.
Minimum thickness specifications are cast on the
rotor's unmachined surface (Fig. 82). Limits can also
be found in this section's specification table. (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/ROTOR -
SPECIFICATIONS)
ROTOR THICKNESS VARIATION
Thickness variation in a rotor's braking surface
can result in pedal pulsation, chatter and surge. This
can also be caused by excessive runout in the rotor or
the hub. Rotor thickness variation measurements should be
made in conjunction with measuring runout. Mea-
sure thickness of the brake rotor at 12 equal points
around the rotor braking surface with a micrometer
at a radius approximately 25 mm (1 inch) from edge
of rotor (Fig. 83). If thickness measurements vary
beyond the specification listed in the specifaction
table (Refer t o 5 - BRAKES/HYDRAULIC/MECHAN-
ICAL/ROTOR - SPECIFICATIONS), the rotor should
be refaced or replaced. (Refer t o 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - STANDARD
PROCEDURE).
ROTOR RUNOUT
On-vehicle rotor runout is the combination of the
individual runout of the hub face and the runout of
the rotor. (The hub and rotor runouts are separable).
To measure rotor runout on the vehicle, first remove
the tire and wheel assembly. Reinstall the wheel
mounting nuts on the studs, tightening the rotor to
the hub. Mount the Dial Indicator, Special Tool
C-3339, with Mounting Adaptor, Special Tool SP-
1910 on steering arm. The dial indicator plunger
should contact braking surface of rotor approximately
ten millimeters from edge of rotor (Fig. 84). Check
lateral runout on both sides of the rotor, marking the
low and high spots on both. Runout limits can be
found in the specification table in this section. (Refer
to 5 - BRAKES/HYDRAULIC/MECHANICAL/RO-
TOR - SPECIFICATIONS)
Fig. 82 Minimum Brake Rotor Thickness Markings (Typical)
1 - ROTOR MINIMUM THICKNESS MARKING
2 - ROTOR
5s - 54 BRAKESRS
PROPORTIONING VALVE (Continued)