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
SERVICE PROCEDURES
MASTER CYLINDER FLUID LEVEL CHECK
Check master cylinder reservoir fluid level a mini-
mum of twice annually.
Master cylinder reservoirs are marked with the
words FULL and ADD to indicate proper brake fluid
fill level of the master cylinder (Fig. 26).
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.When filling master
cylinder fluid reservoir do not fill the filler
neck of the fluid reservoir (Fig. 26) with brake
fluid.
Use only Mopartbrake fluid or an equivalent from
a sealed container. Brake fluid must conform to DOT
3, specifications.
DO NOTuse brake fluid with a lower boiling
point, as brake failure could result during prolonged
hard braking.
Use only brake fluid that was stored in a tightly-
sealed container.
DO NOTuse petroleum-based fluid because seal
damage will result. Petroleum based fluids would be
items such as engine oil, transmission fluid, power
steering fluid ect.
BLEEDING BASE BRAKE HYDRAULIC SYSTEM
NOTE: This bleeding procedure is only for the vehi-
cle's base brakes hydraulic system. For bleeding
the antilock brakes hydraulic system, refer to the
ITT Teves Mark 20 Antilock Brake System bleeding
procedure in the antilock brakes section of this ser-
vice manual.
PRESSURE BLEEDING PROCEDURE
CAUTION: Before removing the master cylinder
cover, throughly clean the cover and master cylin-
der fluid reservoir to prevent dirt and other foreign
matter from dropping into the master cylinder fluid
reservoir.
CAUTION: Use bleeder tank Special Tool C-3496-B
with adapter Special Tool 6921 to pressurize the
hydraulic system for bleeding.
CAUTION: When pressure bleeding the brakes
hydraulic system the fluid reservoir filler neck must
be removed from the master cylinder fluid reservoir.
Failure to remove the filler neck from the fluid res-
ervoir, may result in the filler neck separating from
the fluid reservoir when the hydraulic system is
pressurized.
Follow pressure bleeder manufacturer's instruc-
tions, for use of pressure bleeding equipment.
When bleeding the brake system, some air may be
trapped in the brake lines or valves far upstream, as
much as ten feet from the bleeder screw (Fig. 27).
Therefore, it is essential to have a fast flow of a large
volume of brake fluid when bleeding the brakes to
ensure all the air gets out.
(1) Remove the filler neck from the master cylin-
der fluid reservoir.
(2) Install the Adapter Master Cylinder Pressure
Bleed Cap, Special Tool 6921 on the fluid reservoir of
the master cylinder (Fig. 28). Attach the fluid hose
from the pressure bleeder to the fitting on Special
Tool 6921.
(3) Attach a clear plastic hose to the bleeder screw
at one wheel and feed the hose into a clear jar con-
taining fresh brake fluid.
Fig. 26 Master Cylinder Fluid Level Marks
Fig. 27 Trapped Air In Brake Fluid Line
5 - 20 BRAKESNS
NOTE: The following wheel sequence should be
used when bleeding the brake hydraulic system.
The use of this wheel sequence will ensure ade-
quate removal of all trapped air from the brake
hydraulic system.
²Left Rear Wheel
²Right Front Wheel
²Right Rear Wheel
²Left Front Wheel
(4) Open the left rear wheel bleeder screw at least
one full turnor more to obtain an adequate flow of
brake fluid (Fig. 29).
CAUTION: Just cracking the bleeder screw often
restricts fluid flow, and a slow, weak fluid discharge
will NOT get all the air out.
(5) After 4 to 8 ounces of brake fluid has been bled
through the hydraulic system, and an air-free flow is
maintained in the hose and jar, this will indicate agood bleed of the hydraulic system has been
obtained.
(6) Repeat the procedure at all the other remain-
ing bleeder screws. Then check the pedal for travel.
If pedal travel is excessive or has not been improved,
enough fluid has not passed through the system to
expel all the trapped air. Be sure to monitor the fluid
level in the pressure bleeder, so it stays at a proper
level so air will not enter the brake system through
the master cylinder.
(7) Perform a final adjustment of the rear brake
shoes and then test drive vehicle to be sure brakes
are operating correctly and that pedal is solid.
BLEEDING WITHOUT A PRESSURE BLEEDER
NOTE: Correct manual bleeding of the brakes
hydraulic system will require the aid of a helper.
NOTE: To adequately bleed the brakes using the
manual bleeding procedure the rear brakes must be
correctly adjusted. Prior to the manual bleeding of
the brake hydraulic system, correctly adjust the
rear brakes.
NOTE: The following wheel sequence should be
used when bleeding the brake hydraulic system.
The use of this wheel sequence will ensure ade-
quate removal of all trapped air from the brake
hydraulic system.
²Left Rear Wheel
²Right Front Wheel
²Right Rear Wheel
²Left Front Wheel
(1) Pump the brake pedal three or four times and
hold it down before the bleeder screw is opened.
(2) Push the brake pedal toward the floor and hold
it down. Then open the left rear bleeder screw at
least 1 full turn. When the bleeder screw opens the
brake pedal will drop all the way to the floor.
(3) Release the brake pedal onlyafterthe bleeder
screw is closed.
(4) Repeat steps 1 through 3, four or five times, at
each bleeder screw in the required sequence. This
should pass a sufficient amount of fluid to expel all
the trapped air from the brake system. Be sure to
monitor the fluid level in the master cylinder, so it
stays at a proper level so air will not enter the brake
system through the master cylinder.
(5) Perform a final adjustment of the rear brake
shoes and then test drive vehicle to be sure brakes
are operating correctly and that pedal is solid.Fig. 28 Pressure Bleeding Cap Installed On Master
Cylinder
Fig. 29 Rear Wheel Cylinder Bleeder Screw
NSBRAKES 5 - 21
SERVICE PROCEDURES (Continued)
MASTER CYLINDER BLEEDING PROCEDURE
CAUTION: When clamping master cylinder in vise,
only clamp master cylinder by its mounting flange,
do not clamp on primary piston, seal\boot or body
of master cylinder.
(1) Clamp the master cylinder in a vise using only
the mounting flange (Fig. 30).
NOTE: Two different size bleeding tubes are used
depending on which type of master cylinder the
vehicle is equipped with. Vehicles equipped with
traction control use a center port master cylinder
with a larger diameter brake tube. Vehicles not
equipped with traction control use a compensating
port master cylinder using a standard 3/16 inch
diameter brake tube. Be sure the correct size bleed-
ing tubes are used when bleeding the master cylin-
der.
(2) Install the Bleeding Tubes, Special Tool 6920
for a non traction control master cylinder or Special
Tool 8129 for a traction control master cylinder on
the master cylinder (Fig. 102). Position bleeding
tubes so the outlets of bleeding tubes will be below
surface of brake fluid when reservoir is filled to its
proper level.
(3) Fill brake fluid reservoir with brake fluid con-
forming to DOT 3 specifications such as Mopar or an
Equivalent.
(4) Using a wooden dowel, depress push rod slowly,
and then allow pistons to return to released position.
Repeat several times until all air bubbles are
expelled from master cylinder.
(5) Remove bleeding tubes from master cylinder
outlet ports, and then plug outlet ports and install
fill cap on reservoir.
(6) Remove master cylinder from vise.(7) Install the filler cap from the master cylinder
filler neck, on the master cylinder fluid reservoir.
(8) Install the master cylinder assembly on the
power brake vacuum booster.
NOTE: Note: It is not necessary to bleed the ABS
hydraulic control unit (HCU) after replacing the
master cylinder. But, the base brake hydraulic sys-
tem must be bled to ensure no air is entered the
hydraulic system when the master cylinder was
removed.
ROTOR MACHINING (FRONT/REAR)
BRAKE ROTOR MACHINING PROCEDURES
Any servicing of the rotor requires extreme care to
maintain the rotor to within service tolerances to
ensure proper brake action.
If the rotor surface is deeply scored or warped, or
there is a complaint of brake roughness or brake
pedal pulsation, the rotor should be resurfaced,
refaced (Fig. 32) or (Fig. 33) or replaced.
NOTE: All rotors have markings for minimum
allowable thickness cast on an un-machined sur-
face of the rotor (Fig. 34) or (Fig. 35).
This marking includes 0.76 mm (0.030 inch) allow-
able rotor wear beyond the recommended 0.76 mm
(0.030 inch) of rotor refacing.
The collets, shafts and adapters used on the brake
lathe and the bearing cups in the rotor MUST be
clean and free from any chips or contamination.
When mounting the rotor on the brake lathe, strict
attention to the brake lathe manufacturer's operating
instructions is required.
If the rotor is not mounted properly, the lateral
runout will be worse after refacing or resurfacing
than before.
Fig. 30 Master Cylinder Mounted In Vise
Fig. 31 Bleed Tubes Installed On Master Cylinder
5 - 22 BRAKESNS
SERVICE PROCEDURES (Continued)
NOTE: Two different size bleeding tubes are used
depending on which type of master cylinder the
vehicle is equipped with. Vehicles equipped with
traction control use a center port master cylinder
with a larger diameter brake tube. Vehicles not
equipped with traction control use a compensating
port master cylinder using a standard 3/16 inch
diameter brake tube. Be sure the correct size bleed-
ing tubes are used when bleeding the master cylin-
der.
(2) Install the Bleeding Tubes, Special Tool 6920
for a non traction control master cylinder or Special
Tool 8129 for a traction control master cylinder on
the master cylinder (Fig. 102). Position bleeding
tubes so the outlets of bleeding tubes will be below
surface of brake fluid when reservoir is filled to its
proper level.(3) Fill brake fluid reservoir with brake fluid con-
forming to DOT 3 specifications such as Mopar or an
Equivalent.
(4) Using a wooden dowel, (Fig. 102) depress push
rod slowly, and then allow pistons to return to
released position. Repeat several times until all air
bubbles are expelled from master cylinder.
(5) Remove bleeding tubes from master cylinder
outlet ports, and then plug outlet ports and install
fill cap on reservoir.
(6) Remove master cylinder from vise.
NOTE: Note: It is not necessary to bleed the ABS
hydraulic control unit (HCU) after replacing the
master cylinder. But, the base brake hydraulic sys-
tem must be bled to ensure no air is entered the
hydraulic system when the master cylinder was
removed.
INSTALL
CAUTION: When replacing the master cylinder on
a vehicle, a NEW vacuum seal MUST be installed on
the master cylinder. Use only procedure detailed
below for installing the vacuum seal onto the mas-
ter cylinder.
(1) Install aNEWvacuum seal on master cylinder
making sure seal sits squarely in groove of master
cylinder casting (Fig. 103).
(2) Position master cylinder on studs of power
brake unit, aligning push rod on power brake vac-
uum booster with master cylinder push rod.
(3) Install the 2 master cylinder to power brake
unit mounting nuts. Then tighten both mounting
nuts to a torque of 25 N´m (225 in. lbs.).
Fig. 101 Master Cylinder Correctly Mounted In Vise
Fig. 102 Bleeding Tubes Installed On Master
Cylinder
Fig. 103 Vacuum Seal Installed On Master Cylinder
5 - 46 BRAKESNS
REMOVAL AND INSTALLATION (Continued)
Tighten all 6 tube nuts to a torque of 16 N´m (145 in.
lbs.).
(3) Bleed the brake system thoroughly to ensure
that all air has been expelled from the hydraulic sys-tem. See Bleeding Brake System in the Service
Adjustments section in this group of the service man-
ual for the proper bleeding procedure.
(4) Lower the vehicle.
(5) Road test the vehicle to verify proper operation
of the vehicles brake system.
PROPORTIONING VALVE (W/ABS BRAKES)
The actual proportioning valves of the proportion-
ing valve assembly are not serviceable or replaceable.
If a proportioning valve of the proportioning valve
assembly is not functioning properly, the fixed pro-
portioning valve must be replaced as an assembly.
REMOVE
(1) Using a brake pedal depressor, move and lock
the brake pedal to a position past its first 1 inch of
travel. This will prevent brake fluid from draining
out of the master cylinder when the brake tubes are
removed from the proportioning valve.
(2) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication And Mainte-
nance Group of this service manual.
CAUTION: Before removing the brake tubes from
the proportioning valve, the proportioning valve and
the brake tubes must be thoroughly cleaned. This is
required to prevent contamination from entering the
proportioning valve or the brake tubes.
(3) Remove the 4 chassis brake lines from the inlet
and outlet ports of the proportioning valve (Fig. 132).
(4) Remove the bolts (Fig. 133) attaching the pro-
portioning valve bracket to the frame rail of the vehi-
cle. Remove the fixed proportioning valve assembly
from the vehicle.
Fig. 129 Junction Block Brake Tubes
Fig. 130 Junction Block Mounting
Fig. 131 Brake Tube Connections To Junction Block
Fig. 132 Chassis Brake Tubes At Proportioning
Valve
5 - 56 BRAKESNS
REMOVAL AND INSTALLATION (Continued)
INSTALL
CAUTION: When mounting the original or a
replacement proportioning valve on the frame rail of
the vehicle install the mounting bolts in only the
two forward holes of the mounting bracket (Fig.
133).
(1) Install proportioning valve assembly on the
frame rail of the vehicle. Install the proportioning
valve assembly attaching bolts (Fig. 133). Tighten the
attaching bolts to a torque of 14 N´m (125 in. lbs.).
(2) Install the 4 chassis brake lines (Fig. 132) into
the inlet and outlet ports of the proportioning valve
assembly. Tighten all 4 line nuts to a torque of 16
N´m (142 in. lbs.).
(3) Bleed the brake system thoroughly enough to
ensure that all air has been expelled from the
hydraulic system. See Bleeding Brake System in the
Service Adjustments section in this group of the ser-
vice manual for the proper bleeding procedure.
(4) Lower the vehicle to the ground.
(5) Road test the vehicle to verify proper operation
of the vehicles brake system.
PROPORTIONING VALVE (W/O ABS BRAKES)
The components of the proportioning valve assem-
bly are not serviceable or replaceable. If a component
of the proportioning valve assembly is not function-
ing properly, the proportioning valve must be
replaced as an assembly.
REMOVE
(1) Using a brake pedal depressor, move and lock
the brake pedal to a position past its first 1 inch of
travel. This will prevent brake fluid from draining
out of the master cylinder when the brake tubes are
removed from the proportioning valve.(2) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication And Mainte-
nance Group of this service manual.
CAUTION: Before removing the brake tubes from
the proportioning valve, the proportioning valve and
the brake tubes must be thoroughly cleaned. This is
required to prevent contamination from entering the
proportioning valve or the brake tubes.
(3) Remove the 4 chassis brake tubes from the
inlet and outlet ports of the proportioning valve (Fig.
134).
(4) Remove the 2 bolts (Fig. 135) attaching the
proportioning valve to the proportioning valve
mounting bracket. Remove the proportioning valve
from the mounting bracket.
(5) Remove the hooked end of the proportioning
valve actuator (Fig. 136) from the isolator bushing on
the lever of the height proportioning valve (Fig. 136).
Fig. 133 Proportioning Valve Attachment To Vehicle
Fig. 134 Chassis Brake Tubes At Proportioning
Valve
Fig. 135 Proportioning Valve Mounting
NSBRAKES 5 - 57
REMOVAL AND INSTALLATION (Continued)
INSTALL
(1) Install the hooked end of the actuator on the
proportioning valve lever (Fig. 136).Be sure isola-
tor bushing on lever of proportioning valve
(Fig. 136) is fully seated in hook of actuator.
NOTE: When installing height sensing proportion-
ing valve on mounting bracket be sure proportion-
ing valve shield (Fig. 135) is installed between the
proportioning valve and the mounting bracket.
(2) Install height sensing proportioning valve on
mounting bracket. Install the proportioning valve
attaching bolts (Fig. 135). Tighten the attaching bolts
to a torque of 23 N´m (200 in. lbs.).
(3) Install the 4 chassis brake lines (Fig. 134) into
the inlet and outlet ports of the proportioning valve.
Tighten all 4 line nuts to a torque of 16 N´m (142 in.
lbs.).
(4) Adjust the proportioning valve actuator. See
Height Sensing Proportioning Valve in the Adjust-
ment Section in this group of the service manual for
the adjustment procedure.
(5) Bleed the brake system thoroughly to ensure
that all air has been expelled from the hydraulic sys-
tem. See Bleeding Brake System in the Service
Adjustments section in this group of the service man-
ual for the proper bleeding procedure.
(6) Lower the vehicle to the ground.
(7) Road test the vehicle to verify proper operation
of the vehicles brake system.
HYDRAULIC BRAKE TUBES AND HOSES
CAUTION: When installing brake chassis lines or
flex hoses on the vehicle, the correct fasteners
must be used to attach the routing clips or hoses to
the front suspension cradle. The fasteners used toattach components to the front suspension cradle
have an antiÐcorrosion coating due to the suspen-
sion cradle being made of aluminum. Only Mopar
replacement fasteners with the required anti-corro-
sion coating are to be used if a replacement fas-
tener is required when installing a brake chassis
line or flex hose.
Only double wall 4.75mm (3/16 in.) steel tubing
with Al-rich/ZW-AC alloy coating and the correct tube
nuts are to be used for replacement of a hydraulic
brake tube.
NOTE: On vehicles equipped with traction control,
the primary and secondary hydraulic tubes between
the master cylinder and the hydraulic control unit
are 6 mm (15/64 in.). These tubes are also coated
with the Al-rich/ZW-AC alloy and must be replaced
with tubes having the same anti-corrosion coating.
Be sure that the correct tube nuts are used for the
replacement of these hydraulic brake tubes.
Care should be taken when replacing brake tubing,
to be sure the proper bending and flaring tools and
procedures are used, to avoid kinking. Do not route
the tubes against sharp edges, moving components or
into hot areas. All tubes should be properly attached
with recommended retaining clips.
If the primary or secondary brake tube from the
master cylinder to the ABS Hydraulic Control Unit
(HCU) or the brake tubes from the HCU to the pro-
portioing valve require replacement,onlythe origi-
nal factory brake line containing the flexible section
can be used as the replacement part. This is required
due to cradle movement while the vehicle is in
motion.
PARK BRAKE PEDAL MECHANISM
REMOVE
(1) Disconnect negative (ground) cable from the
battery and isolate cable from battery terminal.
(2) Remove sill scuff plate from left door sill.
(3) Remove the left side kick panel.
(4) Remove the steering column cover from the
lower instrument panel.
(5) Remove the reinforcement from the lower
instrument panel.
(6) Lock out front park brake cable using the fol-
lowing procedure. Grasp the exposed section of the
front park brake cable and pull rearward on it. While
holding the park brake in this position, install a pair
of locking pliers on the front park brake cable just
rearward of the second body outrigger bracket (Fig.
137).
(7) Remove the front park brake cable from the
park brake cable equalizer.
Fig. 136 Actuator Attachment To Proportioning
Valve
5 - 58 BRAKESNS
REMOVAL AND INSTALLATION (Continued)