maintenance CHRYSLER CARAVAN 2003 Workshop Manual
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Page 164 of 2177
tightening sequence to the full specified torque of 135
N´m (100 ft. lbs.).
(13) Lower vehicle.
(14) Pump the brake pedal several times. This will
set the shoes to the brake rotor.
(15) Check and adjust brake fluid level as neces-
sary.
(16) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake shoes.
INSTALLATION - FRONT DISC BRAKE SHOES
(DISC/DRUM BRAKES)
NOTE: Perform steps Step 1 through Step 5on each
side of the vehicle.
(1) Place the brake shoes in the adapter anti-rattle
clips.
(2) Completely retract the caliper piston back into
the bore of the caliper.
CAUTION: Use care when installing the caliper onto
the disc brake adapter to avoid damaging the boots
on the caliper guide pins.
(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.
14).
(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. This will
set the shoes to the brake rotor.
(8) Check and adjust the brake fluid level as nec-
essary.
(9) Road test the vehicle and make several stops to
wear off any foreign material on the brakes and to
seat the brake shoes.
BRAKE PADS/SHOES - REAR
DISC
REMOVAL - REAR DISC BRAKE SHOES
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(2) Remove rear wheel and tire assemblies from
vehicle.
(3) Remove the caliper to adapter guide pin bolts
(Fig. 15).(4) Remove rear caliper from adapter using the fol-
lowing procedure. First rotate front of caliper up
from the adapter. Then pull the rear of the caliper
and the outboard brake shoe anti-rattle clip out from
under the rear abutment on the adapter (Fig. 16).
(5) Support caliper to prevent the weight of the
caliper from damaging the flexible brake hose (Fig.
17).
(6) If the brake rotor needs to be removed it can be
removed by removing the retainer clips and then
pulling the rotor straight off the wheel mounting
studs.
Fig. 15 Caliper Guide Pin Bolts
1 - DISC BRAKE CALIPER
2 - ADAPTER
3 - AXLE
4 - GUIDE PIN BOLTS
5 - DRIVESHAFT (AWD MODELS ONLY)
Fig. 16 Removing/Installing Caliper
1 - LIFT THIS END OF CALIPER AWAY FROM ADAPTER FIRST
2 - DISC BRAKE CALIPER
3 - ADAPTER ABUTMENT
4 - OUTBOARD BRAKE SHOE HOLD DOWN CLIP
5 - OUTBOARD BRAKE SHOE
6 - ROTOR
7 - ADAPTER
RSBRAKES - BASE5-17
BRAKE PADS/SHOES - FRONT (Continued)
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Page 166 of 2177
If the brake shoe assemblies do not require
replacement, be sure to reinstall the brake shoes in
the original position they were removed from.
INSTALLATION - REAR DISC BRAKE SHOES
(1) Completely retract caliper piston back into pis-
ton bore of caliper assembly.
(2) Lubricate both adapter abutments where the
shoes contact with a liberal amount of MopartMul-
tipurpose Lubricant, or equivalent.
(3) If removed, install the brake rotor on the hub,
making sure it is squarely seated on the face of the
hub.
(4) Install the inboard brake shoe into the caliper
piston by firmly pressing it into the piston bore using
your thumbs. Be sure inboard brake shoe is posi-
tioned squarely against the face of the caliper piston.
NOTE: The outboard shoes are different left to
right. They can be identified by a L or R stamped on
the clip.
(5) Install the outboard brake shoe on the disc
brake caliper. Be sure the outboard shoe is positioned
squarely against the outboard fingers of the caliper.
CAUTION: Use care when installing the caliper
assembly onto the adapter, so the caliper guide pin
bushings do not get damaged by the mounting
bosses.
(6) Carefully lower caliper and brake shoes over
rotor and onto adapter, reversing the removal proce-
dure (Fig. 16).
CAUTION: When installing the caliper guide pin
bolts extreme caution should be taken not to
crossthread the guide pin bolts.
(7) Install the caliper guide pin bolts. Tighten the
guide pin bolts to a torque of 35 N´m (26 ft. lbs.).
(8) Install the wheel and tire assembly. Tighten
the wheel mounting 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.).
(9) Lower vehicle.
CAUTION: Before moving vehicle, pump the brake
pedal several times to insure the vehicle has a firm
brake pedal to adequately stop the vehicle.
(10) Pump brake pedal several times to set brake
shoes to rotors.(11) Check fluid level in reservoir.
(12) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake shoe linings.BRAKE PADS/SHOES - REAR
DRUM
REMOVAL - REAR DRUM BRAKE SHOES
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(2) Remove the rear wheel and tire assemblies
from the vehicle.
(3) Remove rear brake drum to hub retaining clips
(if equipped), then remove rear brake drums. (Refer
to 5 - BRAKES/HYDRAULIC/MECHANICAL/DRUM
- REMOVAL)
NOTE: When creating slack in the park brake cables
by locking out the automatic adjuster, (Fig. 19) be
sure that the park brake pedal is in the released
(most upward) position.
(4) Create slack in the rear park brake cables.
Slack is created by grabbing exposed section of front
park brake cable and pulling it down and rearward.
Slack is maintained in the park brake cable by
installing a pair of locking pliers on the park brake
cable just rearward ofonly the rearbody outrigger
bracket. (Fig. 19)
Fig. 19 Locked Out Park Brake Automatic Adjuster
1 - PARK BRAKE CABLE
2 - REAR BODY OUTRIGGER BRACKET
3 - LOCKING PLIERS
RSBRAKES - BASE5-19
BRAKE PADS/SHOES - REAR DISC (Continued)
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Page 170 of 2177
(4) Install the automatic adjuster screw on the
leading brake shoe. Then install the trailing brake
shoe on the park brake actuating lever and park
brake actuating strut (Fig. 27). Position trailing
brake shoe on brake support plate.
(5) Install the brake shoe hold down pin and
spring on the trailing brake shoe (Fig. 26).
(6) Install the brake shoe to brake shoe upper
return spring (Fig. 25).
CAUTION: When installing the tension clip on the
automatic adjuster, it must be located on only the
threaded area of the adjuster assembly (Fig. 24). If
it is located on a non-threaded area of the adjuster,
the function of the automatic adjuster will be
affected.
(7) Install the tension clip (Fig. 24) attaching the
upper return spring to the automatic adjuster assem-
bly.
(8) Install the brake shoe to brake shoe lower
return springs on the brake shoes (Fig. 22) and (Fig.
23).
(9) Install automatic adjustment lever on the lead-
ing brake shoe of the rear brake assembly (Fig. 21).
(10) Install the actuating spring on the automatic
adjustment lever and leading brake shoe assembly
(Fig. 20).
(11) Verify that the automatic adjuster lever has
positive contact with the star wheel on the automatic
adjuster assembly.
(12) When all components of both rear brake
assemblies are correctly and fully installed, remove
the locking pliers from the front park brake cable.(13) Adjust brake shoes assemblies so as not to
interfere with brake drum installation.
(14) Install the rear brake drums on the hubs.
(15) Adjust rear brake shoes.
(16) Install the wheel and tire assembly.
(17) 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.).
(18) Lower the vehicle.
(19) Push the parking brake lever (pedal) to the
floor once and release pedal. This will automatically
remove the slack from and correctly adjust the park-
ing brake cables.
(20) Road test vehicle. The automatic adjuster will
continue the brake adjustment during the road test
of the vehicle.
ADJUSTMENTS
ADJUSTMENT - REAR DRUM BRAKE SHOES
NOTE: Normally, self-adjusting drum brakes do not
require manual brake shoe adjustment. Although, in
the event of a brake shoe replacement, it is advis-
able to make the initial adjustment manually to
speed up the adjusting time.
NOTE: Before raising the vehicle, verify the parking
brake lever is fully released.
(1) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(2) Remove rubber plug from rear brake adjusting
hole in the rear brake support plate.
(3) Insert a thin screwdriver through the adjusting
hole in the support plate and against the star wheel
of the adjusting screw. Move handle of the tool
upward rotating the star wheel until a slight drag is
felt when tire and wheel assembly is rotated.
(4) Insert a second thin screwdriver or piece of
welding rod into brake adjusting hole and push the
adjusting lever out of engagement with the star
wheel.Care should be taken so as not to bend
adjusting lever or distort lever spring.
(5) While holding the adjusting lever out of
engagement, back off the star wheel just enough to
ensure a free wheel with no brake shoe drag.
(6) Repeat the above adjustment at the other rear
wheel.
(7) Install the adjusting hole rubber plugs back in
the rear brake support plates.
(8) Lower the vehicle.
Fig. 31 Park Brake Components Assembled On
Leading Brake Shoe
1 - PARK BRAKE CABLE
2 - LEADING BRAKE SHOE
3 - PARK BRAKE ACTUATING STRUT
4 - PARK BRAKE ACTUATING LEVER
5 - BRAKE SUPPORT PLATE
RSBRAKES - BASE5-23
BRAKE PADS/SHOES - REAR DRUM (Continued)
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Page 171 of 2177
DISC BRAKE CALIPER -
FRONT
REMOVAL
REMOVAL - FRONT DISC BRAKE CALIPER
(DISC/DISC BRAKES)
(1) Depress the brake pedal past its first inch of
travel and hold it in this position using a brake pedal
depressor (holding) tool. This is done to isolate the
master cylinder from the brake hydraulic system dis-
allowing the brake fluid to completely drain out of
the brake fluid reservoir.
(2) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(3) Remove front wheel and tire assembly.
(4) Remove the banjo bolt connecting the brake
hose to the brake caliper. There are two washers (one
on each side of the brake hose fitting) that will come
off with the banjo bolt. Discard these washers.
(5) Remove the 2 caliper guide pin bolts.
(6) Remove the brake caliper from the adapter.
REMOVAL - FRONT DISC BRAKE CALIPER
(DISC/DRUM BRAKES)
(1) Using a brake pedal holding tool, depress the
brake pedal past its first one inch of travel and hold
it in this position. This will isolate the master cylin-
der from the brake hydraulic system and will not
allow the brake fluid to drain out of the master cyl-
inder reservoir when the lines are opened.
(2) Raise the vehicle. Refer to HOISTING in
LUBRICATION AND MAINTENANCE.
(3) Remove the front tire and wheel assembly.
(4) Remove the banjo bolt connecting the brake
hose to the brake caliper (Fig. 32). There are two
washers (one on each side of the flex hose fitting)
that will come off with the banjo bolt. Discard the
washers.
(5) Remove the two brake caliper guide pin bolts
(Fig. 32).
(6) Remove the disc brake caliper from the disc
brake adapter.
DISASSEMBLY
DISASSEMBLY - CALIPER GUIDE PIN
BUSHINGS (DISC/DISC BRAKES)
Before disassembling the brake caliper, clean and
inspect it. Refer to CLEANING or INSPECTION in
this section.(1) Using your fingers, collapse one side of the rub-
ber guide pin bushing. Pull the guide pin bushing out
the other side of the brake caliper mounting boss.
(2) Repeat this procedure on the remaining bush-
ing.
DISASSEMBLY - CALIPER PISTON AND SEAL
WARNING: UNDER NO CONDITION SHOULD HIGH
PRESSURE AIR EVER BE USED TO REMOVE A PIS-
TON FROM A CALIPER BORE. PERSONAL INJURY
COULD RESULT FROM SUCH A PRACTICE.
NOTE: Before disassembling the brake caliper,
clean and inspect it. Refer to CLEANING AND
INSPECTION in this section.
NOTE: The safest way to remove the piston from
the caliper bore is to use the hydraulic pressure of
the vehicle's brake system.
(1) Following the removal procedure in DISC
BRAKE SHOES found in this section, remove the
caliper from the brake rotor and hang the assembly
on a wire hook away from rotor and body of the vehi-
cle so brake fluid cannot get on these components.
Remove the brake shoes, and place a small piece of
wood between the piston and caliper fingers.
(2) Carefully depress the brake pedal to hydrauli-
cally push piston out of its bore. Once completed,
apply and hold down the brake pedal to any position
beyond the first inch of pedal travel using a brake
pedal holding tool. This will prevent the fluid in the
Fig. 32 Brake Caliper Mounting (Typical)
1 - BRAKE HOSE
2 - ADAPTER MOUNTING BOLTS
3 - BANJO BOLT
4 - CALIPER GUIDE PIN BOLTS
5 - 24 BRAKES - BASERS
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Page 175 of 2177
(1) Depress the brake pedal past its first inch of
travel and hold it in this position using a brake pedal
depressor (holding) tool. This is done to isolate the
master cylinder from the brake hydraulic system dis-
allowing the brake fluid to completely drain out of
the brake fluid reservoir.
(2) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(3) Remove rear wheel and tire assembly from
vehicle.
(4) Remove the banjo bolt connecting the brake
hose to the brake caliper. There are two washers (one
on each side of the brake hose fitting) that will come
off with the banjo bolt. Discard these washers.
(5) Remove the disc brake caliper to adapter guide
pin bolts (Fig. 37).
(6) Remove rear caliper from adapter using the fol-
lowing procedure. First rotate front of caliper up
from the adapter. Then pull the rear of the caliper
and the outboard brake shoe anti-rattle clip out from
under the rear abutment on the adapter (Fig. 38).
(7) If the brake rotor requires removal, it can now
be removed by first removing the retainer clips from
the wheel mounting studs, then pulling the rotor
straight off the studs.
DISASSEMBLY - CALIPER PISTON AND SEAL
WARNING: UNDER NO CONDITION SHOULD HIGH
PRESSURE AIR EVER BE USED TO REMOVE A PIS-
TON FROM A CALIPER BORE. PERSONAL INJURY
COULD RESULT FROM SUCH A PRACTICE.NOTE: Before disassembling the brake caliper,
clean and inspect it. Refer to CLEANING AND
INSPECTION in this section.
NOTE: The safest way to remove the piston from
the caliper bore is to use the hydraulic pressure of
the vehicle's brake system.
(1) Following the removal procedure in DISC
BRAKE SHOES found in this section, remove the
caliper from the brake rotor and hang the assembly
on a wire hook away from rotor and body of the vehi-
cle so brake fluid cannot get on these components.
Remove the brake shoes, and place a small piece of
wood between the piston and caliper fingers.
(2) Carefully depress the brake pedal to hydrauli-
cally push piston out of its bore. Once completed,
apply and hold down the brake pedal to any position
beyond the first inch of pedal travel using a brake
pedal holding tool. This will prevent the fluid in the
master cylinder reservoir from completely draining
out.
(3) Disconnect the brake fluid flex hose from the
caliper assembly and remove it from the vehicle.
CAUTION: Do not use excessive force when clamp-
ing caliper in vise. Excessive vise pressure will
cause bore distortion.
(4) Mount the caliper in a vise equipped with pro-
tective jaws.
(5) Remove the piston dust boot from the caliper
and discard.
Fig. 37 Caliper Guide Pin Bolts
1 - DISC BRAKE CALIPER
2 - ADAPTER
3 - AXLE
4 - GUIDE PIN BOLTS
5 - DRIVESHAFT (AWD MODELS ONLY)
Fig. 38 Removing/Installing Caliper
1 - LIFT THIS END OF CALIPER AWAY FROM ADAPTER FIRST
2 - DISC BRAKE CALIPER
3 - ADAPTER ABUTMENT
4 - OUTBOARD BRAKE SHOE HOLD DOWN CLIP
5 - OUTBOARD BRAKE SHOE
6 - ROTOR
7 - ADAPTER
5 - 28 BRAKES - BASERS
DISC BRAKE CALIPER - REAR (Continued)
ProCarManuals.com
Page 178 of 2177
(7) 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.).
(8) Lower the vehicle.
(9) Remove the brake pedal depressor (holding)
tool.
(10) Bleed the hydraulic brake circuit to the brake
caliper. (Refer to 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 to 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
DacrometTcoating applied to resist corrosion. If
mounting bolts need to be replaced, use only
MoparTreplacement 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 to 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
(DISC/DRUM 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. 43).
(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. 44).
INSTALLATION - DISC BRAKE CALIPER GUIDE
PINS (DISC/DRUM 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. 44). 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. 43 Brake Caliper Mounting
1 - BRAKE HOSE
2 - ADAPTER MOUNTING BOLTS
3 - BANJO BOLT
4 - CALIPER GUIDE PIN BOLTS
RSBRAKES - BASE5-31
DISC BRAKE CALIPER - REAR (Continued)
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Page 179 of 2177
(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.
43).
(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 down 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 pro-
cedure found in the Adjustment section of this ser-
vice manual group (Refer to 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 Mopartbrake fluid or equivalent from a
sealed container. Brake fluid must conform to DOT 3
specifications (DOT 4 or DOT 4+ are acceptable).
DO NOTuse brake fluid with a lower boiling
point, as brake failure could result during prolonged
hard braking.
Fig. 44 Guide Pins And Boots
1 - PINS
2 - BOOTS
5 - 32 BRAKES - BASERS
DISC BRAKE CALIPER GUIDE PINS (Continued)
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Page 196 of 2177
Here is how the height sensing proportioning valve
differs from a standard proportioning valve. As the
height of the rear suspension changes, the height
sensing portion of the proportioning valve changes
the split point of the proportioning valve. When the
height of the rear suspension is low, the proportion-
ing valve interprets this as extra load and the split
point of the proportioning valve is raised to a higher
pressure to allow for more rear braking. When the
height of the rear suspension is high, the proportion-
ing valve interprets this as a light load and the split
point of the proportioning valve is lowered to a lower
pressure and rear braking is reduced.
The height sensing proportioning valve regulates
the pressure by sensing the load condition of the
vehicle through the movement of the proportioning
valve actuator lever (Fig. 72). As the position of the
rear axle changes, depending on the load the vehicle
is carrying, the movement is transferred to the pro-
portioning valve. The proportioning valve adjusts the
hydraulic pressure accordingly.
The height sensing proportioning valve allows the
brake system to maintain the optimal front to rear
brake balance regardless of the vehicle load condi-
tion. Under a light load condition, hydraulic pressure
to the rear brakes is minimized. As the rear load con-
dition increases, so does the hydraulic pressure to
the rear brakes.
DIAGNOSIS AND TESTING - PROPORTIONING
VALVE (HEIGHT SENSING)
CAUTION: The use of aftermarket load leveling or
load capacity increasing devices on this vehicle is
prohibited. Using air shock absorbers or helpersprings 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.
When a premature rear wheel skid is obtained on a
brake application, it may be an indication that the
hydraulic pressure to the rear brakes is above the
specified output from the proportioning valve. This
condition indicates a possible malfunction of the
height sensing proportioning valve, which will
require testing to verify that it is properly controlling
the hydraulic pressure allowed to the rear brakes.
Premature rear wheel skid may also be caused by
contaminated front or rear brake linings.
Prior to testing a proportioning valve for function,
check that all tire pressures are correct. Also, ensure
the front and rear brake linings are in satisfactory
condition.It is also necessary to verify that the
brakes shoe assemblies on a vehicle being
tested are either original equipment manufac-
turers (OEM) or original replacement brake
shoe assemblies meeting the OEM lining mate-
rial specification. This vehicles brake system is
not balanced for aftermarket brake shoe assem-
bly lining material.
If both front and rear brakes check OK, proceed
with the following test procedure for the height sens-
ing proportioning valve.
(1) Road test the vehicle to determine which rear
wheel brake is exhibiting premature wheel skid.
(2) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(3) Remove the chassis brake tube going to the
rear brake in question at the proportioning valve.
Remove the chassis brake tube coming from the junc-
tion block at the proportioning valve (Fig. 73).
(4) Install the appropriate fittings from Pressure
Test Fittings, Special Tool 6833, into the open ports
of the proportioning valve.
(5) Install the previously removed brake lines into
the Pressure Test Fittings. Tighten all tube nuts to
17 N´m (145 in. lbs.).
(6) Install a pressure gauge from Gauge Set, Spe-
cial Tool C-4007-A into the open port on each pres-
sure test fitting. Bleed air out of hose from pressure
test fittings to pressure gauges at the pressure
gauges. Then bleed air out of the brake line being
tested at that rear wheel brake bleeder.
NOTE: Actuator rod is a linear spring and is meant
to flex by design. When rod is raised, it will have
some curvature to it.
Fig. 72 HEIGHT SENSING PROPORTIONING VALVE
1 - PROPORTIONING VALVE
2 - ACTUATOR LEVER
3 - AXLE BRACKET
4 - REAR AXLE
RSBRAKES - BASE5-49
PROPORTIONING VALVE (Continued)
ProCarManuals.com
Page 197 of 2177
(7) Remove the screw fastening the proportioning
valve actuator rod bracket to the rear axle. Raise the
actuator lever to the full-upward position and hold it
there.
(8) With the aid of a helper, apply pressure to the
brake pedal until a pressure of 6895 kPa (1000 psi) is
obtained on the proportioning valve inlet gauge.
Then, based on the type of brake system the vehicle
is equipped with and the pressure specification
shown on the following table, compare the pressure
reading on the outlet gauge to the specification. If
outlet pressure at the proportioning valve is not
within specification when required inlet pressure is
obtained, replace the proportioning valve. (Refer to 5
- BRAKES/HYDRAULIC/MECHANICAL/PROPOR-
TIONING VALVE - REMOVAL)
CAUTION: Do not attempt to adjust the height sens-
ing proportioning valve. If found to be defective,
replace the valve.(9) Remove the pressure test fittings and pressure
gauges from the proportioning valve.
(10) Install the chassis brake lines in the correct
ports of the proportioning valve. Tighten all tube
nuts to 17 N´m (145 in. lbs.).
(11) If necessary, repeat the above steps on the
remaining side of the proportioning valve which con-
trol the other rear wheel brake.
(12) Attach the actuator lever and bracket to the
rear axle.
(13) Bleed rear brakes. (Refer to 5 - BRAKES -
STANDARD PROCEDURE)
(14) Road test vehicle.
PROPORTIONING VALVE SPECIFICATIONS
WHEEL
BASEDRIVE
TRAINSALES CODE BRAKE SYSTEMSPLIT
POINTSLOPEINLET
PRESSURE
PSIOUTLET
PRESSURE
PSI
SWB FWD BRB-BGF159DISC/DRUM
W/O ANTILOCKVAR. .59 1000 PSI 675-875 PSI
REMOVAL - PROPORTIONING VALVE (HEIGHT
SENSING)
(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. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
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 four brake tubes from the inlet and
outlet ports of the proportioning valve (Fig. 73).
(4) Remove the two bolts attaching the proportion-
ing valve and bracket to the vehicle (Fig. 73).
(5) Slide the bracket out from under rear track bar
bracket. Lower the valve down enough to pull its
actuator rod out of the axle bracket and remove the
proportioning valve from the vehicle.
Fig. 73 PROPORTIONING VALVE MOUNTING
1 - LEFT REAR OUTLET TUBE
2 - RIGHT REAR OUTLET TUBE
3 - RIGHT REAR INLET TUBE
4 - MOUNTING BOLTS
5 - LEFT REAR INLET TUBE
5 - 50 BRAKES - BASERS
PROPORTIONING VALVE (Continued)
ProCarManuals.com
Page 201 of 2177
Before installation, verify the brake rotor face and
the hub adapters are free of any chips, rust, or con-
tamination.
When mounting and using the brake lathe, strict
attention to the brake lathe manufacturer's operating
instructions is required.
Machine both sides of the brake rotor at the same
time. Cutting both sides at the same time minimizes
the possibility of a tapered or uneven cut.
When refacing a rotor, the required TIR (Total
Indicator Reading) and thickness variation limits
MUST BE MAINTAINED. Extreme care in the oper-
ation of rotor turning equipment is required. Specifi-
cations for brake rotor machining can be found in
this section's specification table. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTOR -
SPECIFICATIONS)
REMOVAL - FRONT BRAKE ROTOR
(1) Raise vehicle on jackstands or centered on a
frame contact type hoist. See Hoisting in Lubrication
and Maintenance.
(2) Remove the front wheel and tire assembly.(3) Remove the two mounting bolts securing the
disc brake caliper adapter with brake caliper to the
steering knuckle (Fig. 83).
(4) Remove the disc brake caliper and adapter as
an assembly from the steering knuckle (Fig. 83).
Hang the assembly out of the way using wire or a
bungee cord. Use care not to overextend the brake
hose when doing this.
(5) Remove any retainer clips from the wheel
mounting studs.
(6) Remove brake rotor from hub by pulling it
straight off wheel mounting studs (Fig. 83).
INSTALLATION - FRONT BRAKE ROTOR
(1) Install the brake rotor back on the hub and
bearing (Fig. 83).
(2) Install brake caliper and adapter back over
brake rotor aligning adapter with mounting holes on
steering knuckle (Fig. 83).
(3) Install the two adapter mounting bolts securing
the adapter to the steering knuckle. Tighten the
mounting bolts to 169 N´m (125 ft. lbs.) torque.
(4) Install wheel and tire assembly on vehicle.
Tighten the wheel mounting lug nuts in proper
sequence until all nuts are torqued to half specifica-
tion, then repeat the tightening sequence to the full
specified torque of 135 N´m (100 ft. lbs.).
(5) Lower vehicle to the ground.
Fig. 81 Front Brake Rotor
1 - ROTOR MINIMUM THICKNESS MARKING
2 - ROTOR
Fig. 82 Rear Brake Rotor Minimum Thickness
Markings
1 - ROTOR MINIMUM THICKNESS AND DRUM MAXIMUM
DIAMETER SPECIFICATIONS ARE SHOWN ON THIS SURFACE
2 - REAR ROTOR
Fig. 83 Front Brake Mounting
1 - BRAKE ROTOR
2 - HUB AND BEARING
3 - STEERING KNUCKLE
4 - ADAPTER MOUNTING BOLTS
5 - BRAKE CALIPER
6 - ADAPTER
7 - CLIP
5 - 54 BRAKES - BASERS
ROTOR (Continued)
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