2004 CHRYSLER VOYAGER torque

CAUTION: 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 body of the master cylinder is an anodized alu-
minum casting. It has a machined bore to accept the
master cylinder pistons and threaded ports with
seats for the hydraulic brake line connections.
The brake fluid reservoir is mounted on the top of
the master cylinder. It is made of a see-through
polypropylene type plastic for easy fluid level view-
ing. A brake fluid level switch is attached to the
brake fluid reservoir.
The master cylinder is not a repairable component
and must be replaced if diagnosed to be functioning
improperly. The brake fluid reservoir and brake fluid
level switch can be replaced separately.
CAUTION: Do not hone the bore of the cylinder as
this will remove the anodized surface from the bore.
DESCRIPTION - RHD
The master cylinder used on right hand drive
(RHD) vehicles functions similarly to that used on
left hand drive (LHD) vehicles. The RHD master cyl-
inder, as well as the RHD power brake booster, is
located in the same area, but lower in the engine
compartment than LHD models (Fig. 47). For that
reason an extension manifold is placed between the
fluid reservoir and master cylinder housing allowing
the fluid reservoir to be positioned in the same loca-
tion as on LHD models.
OPERATION
When the brake pedal is depressed, the master cyl-
inder primary and secondary pistons apply brake
pressure through the chassis tubes to the brakes at
each tire and wheel assembly.
The master cylinder primary outlet port supplies
hydraulic pressure to the right front and left rear
brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
STANDARD PROCEDURE - MASTER CYLINDER
BLEEDING
CAUTION: When clamping master cylinder in vise,
only clamp master cylinder by its mounting flange.
Do not clamp master cylinder piston rod, reservoir,
seal or body.
(1) Clamp master cylinder in a vise.
NOTE: Use correct bleeder tubes when bleeding
master cylinder. Master cylinder outlet ports vary in
size and type depending on whether master cylin-
der is for a vehicle equipped with traction control or
not. Traction control equipped master cylinders
require the additional use of ISO style flare adapt-
ers supplied in Special Tool Package 8822 to be
used in conjunction with Bleeder Tubes, Special
Tool Package 8358.
(2) Attach special tools for bleeding master cylin-
der in the following fashion:
(a)For non-traction control equipped mas-
ter cylinders, thread a Bleeder Tube, Special Tool
8358±1, into each outlet port. Tighten each tube to
17 N´m (145 in. lbs.) torque. Flex bleeder tubes and
place open ends into mouth of fluid reservoir as far
down as possible (Fig. 48).
(b)For traction control equipped master
cylinders, thread one Adapter, Special Tool
8822±2, in each outlet port. Tighten Adapters to 17
N´m (145 in. lbs.) torque. Next, thread a Bleeder
Tube, Special Tool 8358±1, into each Adapter.
Tighten each tube to 17 N´m (145 in. lbs.) torque.
Flex bleeder tubes and place open ends into mouth
of fluid reservoir as far down as possible (Fig. 48).
NOTE: Make sure open ends of bleeder tubes stay
below surface of brake fluid once reservoir is filled
to proper level.
(3) Fill brake fluid reservoir with Mopartbrake
fluid or equivalent conforming to DOT 3 (DOT 4 and
DOT 4+ are acceptable) specifications. Make sure
fluid level is above tips of bleeder tubes in reservoir
to ensure no air is ingested during bleeding.
Fig. 47 RHD MASTER CYLINDER AND POWER
BRAKE BOOSTER
1 - POWER BRAKE BOOSTER
2 - BRAKE FLUID LEVEL SWITCH
3 - FLUID RESERVOIR
4 - MASTER CYLINDER
RSBRAKES - BASE5-35
MASTER CYLINDER (Continued)

(2) Remove brake fluid reservoir cap. Using a
syringe or equivalent type tool empty as much brake
fluid as possible from the reservoir.
CAUTION: When removing fluid reservoir from the
master cylinder, do not pry off using any type of
tool. This can damage the fluid reservoir or master
cylinder housing.
(3) Remove the master cylinder assembly from the
power brake vacuum booster. (Refer to 5 - BRAKES -
BASE/HYDRAULIC/MECHANICAL/MASTER CYL-
INDER - REMOVAL).
(4) Mount the master cylinder in a vise using the
master cylinder mounting flange.
(5) Using correct size pin punch, remove the two
retaining pins between the fluid reservoir and master
cylinder housing (Fig. 52).
(6) Rock the brake fluid reservoir from side to side
while pulling up to remove it from the seal grommets
in master cylinder housing.
(7) Remove the two master cylinder housing to
brake fluid reservoir seal grommets (Fig. 53).
ASSEMBLY - MASTER CYLINDER (FLUID
RESERVOIR)
(1) Install new master cylinder housing to brake
fluid reservoir sealing grommets in master cylinder
housing (Fig. 53).
(2) Lubricate reservoir mounting area with fresh
clean brake fluid. Place reservoir in position over
sealing grommets. Seat reservoir into sealing grom-
mets using a rocking motion while firmly pressing
down on fluid reservoir.
(3) Be sure fluid reservoir is positioned properly on
master cylinder.Bottom of fluid reservoir is to betouching the top of both sealing grommets
when properly installed on master cylinder
housing.
(4) Install the two fluid reservoir to master cylin-
der retaining pins (Fig. 52).
(5) Install the master cylinder assembly on the
power brake booster. (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/MASTER CYLINDER -
INSTALLATION)
(6) Fill fluid reservoir to its proper level as indi-
cated on the side of the fluid reservoir.
INSTALLATION
INSTALLATION - LHD
CAUTION: Different types of master cylinders are
used on this vehicle depending on brake options. If
a new master cylinder is being installed, be sure it
is the correct master cylinder for the type of brake
system the vehicle is equipped with.
CAUTION: When replacing the master cylinder on a
vehicle, a NEW vacuum seal MUST be installed on
the master cylinder.
(1) Install a NEW vacuum seal on master cylinder
making sure seal fits squarely in groove of master
cylinder casting.
(2) Position master cylinder on studs of power
brake booster, aligning booster push rod with master
cylinder piston.
(3) Install the two master cylinder mounting nuts
(Fig. 50). Tighten both mounting nuts to a torque of
25 N´m (225 in. lbs.).
Fig. 52 Fluid Reservoir Retaining Pins (Typical)
1 - FLUID RESERVOIR
2 - RETAINING PINS
3 - MASTER CYLINDER
Fig. 53 Master Cylinder To Fluid Reservoir Seal
Grommets
1 - SEAL GROMMETS
2 - MASTER CYLINDER
5 - 38 BRAKES - BASERS
MASTER CYLINDER (Continued)

CAUTION: When tightening the primary and sec-
ondary brake tube nuts at master cylinder, be sure
brake tubes do not contact any other components
within the vehicle and that there is slack in the flex-
ible sections of the tubes. This is required due to
the movement between the ABS ICU and the master
cylinder while the vehicle is in motion.
(4) Connect primary and secondary brake tubes to
master cylinder primary and secondary ports (Fig.
49). Brake tubes must be held securely when tight-
ened to control orientation of flex section. Tighten
tube nuts to a torque of 17 N´m (145 in. lbs.).
(5) Install wiring harness connector to brake fluid
level switch mounted in brake fluid reservoir (Fig.
49).
(6) Install battery, clamp and nut.
(7) Install battery shield.
(8) Connect positive battery terminal.
(9) Connect negative battery terminal.
(10) Fill master cylinder with clean, fresh Mopart
Brake Fluid or equivalent.
(11) Road test vehicle to ensure proper operation of
brakes.
INSTALLATION - RHD
CAUTION: Different types of master cylinders are
used on this vehicle depending on brake options. If
a new master cylinder is being installed, be sure it
is the correct master cylinder for the type of brake
system the vehicle is equipped with.
CAUTION: When replacing the master cylinder on a
vehicle, a NEW vacuum seal MUST be installed on
the master cylinder.
(1) Install a NEW vacuum seal on master cylinder
making sure seal fits squarely in groove of master
cylinder casting.
(2) Position master cylinder on studs of power
brake booster, aligning booster push rod with master
cylinder piston.
(3) Install the two master cylinder mounting nuts
(Fig. 51). Tighten both mounting nuts to a torque of
25 N´m (225 in. lbs.).
CAUTION: When tightening the primary and sec-
ondary brake tube nuts at master cylinder, be sure
brake tubes do not contact any other components
within the vehicle and that there is slack in the flex-
ible sections of the tubes. This is required due to
the movement between the ABS ICU and the master
cylinder while the vehicle is in motion.(4) Connect primary and secondary brake tubes to
master cylinder primary and secondary ports (Fig.
51). Brake tubes must be held securely when tight-
ened to control orientation of flex section. Tighten
tube nuts to a torque of 17 N´m (145 in. lbs.).
(5) Install wiring harness connector to brake fluid
level switch mounted in brake fluid reservoir (Fig.
47).
(6) Install battery, clamp and nut.
(7) Install battery shield.
(8) Connect positive battery terminal.
(9) Connect negative battery terminal.
(10) Fill master cylinder with clean, fresh Mopart
Brake Fluid or equivalent.
(11) Road test vehicle to ensure proper operation of
brakes.
PEDAL TORQUE SHAFT - RHD
REMOVAL
(1) Remove the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL)
(2) Remove the HVAC housing. (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL)
(3) Remove the retaining clip at the torque shaft
end of the brake pedal-to-torque shaft link. Remove
the link from the torque shaft. Discard the retaining
clip. It is not to be reused. Replace with a new clip
when reassembled.
(4) Locate the booster input rod-to-brake pedal
torque shaft connection and remove the retaining clip
(Fig. 54). Discard the retaining clip. It is not to be
reused. Replace with a new clip when reassembled.
(5) Remove the four (4) brake booster retaining
nuts from inside the passenger compartment (Fig.
55).
(6) Remove the retaining nut from the brake
booster bracket located above the booster in the
engine compartment (Fig. 55).
(7) Remove the power brake booster bracket.
(8) Rotate the pedal torque shaft and remove it out
the left side of the vehicle.
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.).
RSBRAKES - BASE5-39
MASTER CYLINDER (Continued)

(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. 54).
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 to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer to 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. 56).
The master cylinder is bolted to the front of the
booster. A vacuum line connects the power brake
booster to the intake manifold.
All vehicles use a 270 mm single diaphragm vac-
uum 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.
Fig. 54 POWER BRAKE BOOSTER BRACKET
1 - BOOSTER BRACKET
2 - PEDAL TORQUE SHAFT
3 - RETAINING CLIP
4 - BOOSTER MOUNTING NUTS
Fig. 55 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
5 - 40 BRAKES - BASERS
PEDAL TORQUE SHAFT - RHD (Continued)

CAUTION: A seal on the rear of the master cylinder
is used to create the seal for holding vacuum in the
power brake vacuum booster. The vacuum seal on
the master cylinder MUST be replaced whenever the
master cylinder is removed from the power brake
vacuum booster.
(14) Disconnect vacuum hose from check valve
located on booster.DO NOT REMOVE CHECK
VALVE FROM POWER BRAKE BOOSTER.
(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. 65).
(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. 66). 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. 67).
CAUTION: Do not attempt to disassemble the power
brake vacuum booster. It is serviced ONLY as a
complete assembly.
Fig. 64 RHD Master Cylinder Mounting
1 - PRIMARY BRAKE TUBE NUT
2 - SECONDARY BRAKE TUBE NUT
3 - MASTER CYLINDER MOUNTING NUTS
Fig. 65 Booster Input Rod Pin Retaining Clip
(Typical)
1 - BRAKE PEDAL
2 - INPUT ROD
3 - SCREWDRIVER
4 - RETAINING CLIP
5 - BRAKE PEDAL PIN
Fig. 66 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
RSBRAKES - BASE5-45
POWER BRAKE BOOSTER (Continued)

INSTALLATION
INSTALLATION - LHD
(1) Position power brake booster on dash panel
using the reverse procedure of its removal (Fig. 62).
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. 61). 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. 68).
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 to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer to 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. 69).
(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. 59). 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. 58).
(13) Connect primary and secondary brake tubes
to ABS ICU or non-ABS junction block (Fig. 59).
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. 67 RHD Booster Removal/Installation
1 - POWER BRAKE BOOSTER
2 - MASTER CYLINDER
Fig. 68 Retaining Pin Installed On Brake Pedal Pin
1 - BRAKE PEDAL
2 - RETAINING CLIP
3 - BOOSTER INPUT ROD
5 - 46 BRAKES - BASERS
POWER BRAKE BOOSTER (Continued)

the mounting nuts to a torque of 14 N´m (124 in.
lbs.).
(16) 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.).
(17) If vehicle is equipped with speed control, con-
nect the servo vacuum hose to the vacuum tank on
the battery tray.
(18) Install the air inlet resonator and hoses as an
assembly on the throttle body and air cleaner hous-
ing. Securely tighten hose clamp at air cleaner hous-
ing and throttle body.
(19) Secure the engine coolant filler neck to the
battery tray with its mounting screw.
(20) Install the battery, clamp and mounting nut.
(21) Install the positive battery cable on the bat-
tery.
(22) Install the negative battery cable on the bat-
tery.
(23) Install the battery thermal guard shield.
(24) Bleed the base brakes as necessary. (Refer to
5 - BRAKES - STANDARD PROCEDURE)
(25) Road test vehicle to ensure operation of the
brakes.
INSTALLATION - RHD
(1) Position power brake booster on dash panel
using the reverse procedure of its removal (Fig. 67).
(2) Below instrument panel, first install the two
upper nuts mounting the booster to the dash panel,
drawing it into place, then install the two lower
mounting nuts. 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 torque shaft pin where it con-
tacts the booster input rod.CAUTION: When installing the brake pedal torque
shaft pin on the power brake booster input rod, do
not re-use the old retaining clip.
(4) Install booster input rod on brake pedal torque
shaft pin and install a NEW retaining clip (Fig. 70).
(5) Install booster input rod trim cover.
(6) 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.
(7) Using a soft tool such as a trim stick, remove
the vacuum seal from the master cylinder mounting
flange.
(8) Install a NEW vacuum seal on rear mounting
flange of the master cylinder (Fig. 71).
(9) Position master cylinder on studs of booster,
aligning push rod on booster with master cylinder
piston.
(10) Install the two nuts mounting the master cyl-
inder to the booster (Fig. 64). Tighten both mounting
nuts to a torque of 25 N´m (225 in. lbs.).
(11) Connect wiring harness connector to brake
fluid level switch in the master cylinder fluid reser-
voir (Fig. 63).
Fig. 69 Vacuum Seal (Typical)
1 - MASTER CYLINDER ASSEMBLY
2 - VACUUM SEAL
Fig. 70 Retaining Pin Installed On Brake Pedal Pin
(Typical)
1 - BRAKE PEDAL
2 - RETAINING CLIP
3 - BOOSTER INPUT ROD
RSBRAKES - BASE5-47
POWER BRAKE BOOSTER (Continued)

(12) If the vehicle is equipped with the 2.5L diesel
engine, install the coolant recovery pressure con-
tainer and bracket. (Refer to 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 to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - REMOVAL), (Refer to 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. 72). 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
brakes will be lower than the front brakes. This will
prevent premature rear wheel lockup and skid.
Fig. 71 Vacuum Seal (Typical)
1 - MASTER CYLINDER ASSEMBLY
2 - VACUUM SEAL
5 - 48 BRAKES - BASERS
POWER BRAKE BOOSTER (Continued)