Chrysler Sebring, Stratus sedan, Sebring Convertible. Manual — part 289
INSTALLATION - POWER BRAKE BOOSTER
(1) Position power brake booster onto dash panel.
(2) Install and torque the 4 power brake vacuum
booster mounting nuts (Fig. 52) to 29 N·m (250 in.
lbs.) torque.
(3) Using lubriplate, or an equivalent, coat the sur-
faces of the brake pedal pin that contact the power
brake vacuum booster input rod.
(4) Connect power brake vacuum booster input rod
to brake pedal pin and install a NEW retaining clip.
Use only a new retainer clip DO NOT USE the
old clip.
(5) Install the purge solenoid to the left frame rail
and connect its wiring harness (Fig. 50).
(6) Install the vacuum hoses on the booster check
valve.
(7) Install the master cylinder and connect the
fluid level switch. (Refer to 5 - BRAKES/HYDRAU-
LIC/MECHANICAL/MASTER CYLINDER - INSTAL-
LATION)
(8) If equipped, install speed control servo on the
mounting studs. Install the 2 speed control servo
bracket mounting nuts and tighten to a torque of 6
N·m (55 in. lbs.). Install electrical connector and vac-
uum hose on speed control servo.
(9) Install the throttle cable, and if equipped, the
speed control cable on the cam of the throttle body
assembly.
(10) Install the remote ground cable on the ground
stud located on the left strut tower. Install and
securely tighten the ground cable attaching nut.
(11) Check brake lamp operation. If required,
adjust brake lamp switch as necessary. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING
-
EXTERIOR/
BRAKE LAMP SWITCH - ADJUSTMENTS)
(12) Road test vehicle to ensure proper operation
of the vehicles brake system and speed control.
PROPORTIONING VALVE
DESCRIPTION
Proportioning valves are included on vehicles
without antilock brakes (ABS). They are located in
the junction block. (Refer to 5 - BRAKES/HYDRAU-
LIC/MECHANICAL/JUNCTION BLOCK - DESCRIP-
TION)
NOTE: Vehicles with ABS do not have proportioning
valves. They have electronic variable brake propor-
tioning (EVBP).
OPERATION
Proportioning valves balance front to rear braking
by controlling (at a given ratio) brake hydraulic pres-
sure to the rear brakes above a preset level (split
point). On light pedal applications equal brake pres-
sure is transmitted to both the front and rear brakes.
On heavier pedal applications, through the use of
proportioning valves, the pressure transmitted to the
rear will be lower than the front brakes. This pre-
vents premature rear wheel skid.
If hydraulic pressure is lost in one-half of the diag-
onally split brake hydraulic system, the operation of
the proportioning valve in the remaining half is not
affected.
DIAGNOSIS AND TESTING - PROPORTIONING
VALVE
NOTE: The following procedure is designed for
vehicles NOT equipped with ABS.
Vehicles without Antilock Brakes have two propor-
tioning valves. One proportioning valve controls the
right rear brake, and the other proportioning valve
controls the left rear brake. The proportioning valves
are located in the junction block. Vehicle’s with ABS
do not have proportioning valves to test, they use
Electronic Variable Brake Proportioning which is
built into the Integrated Control Unit (ICU).
If premature wheel skid occurs on a hard brake
application, it could be an indication that a malfunc-
tion has occurred with one of the two rear brake pro-
portioning valves. Test the valve that controls the
side of the vehicle on which the skid occurs. Both
proportioning valves have the same pressure specifi-
cations and are tested in the same way.
(1) Clean any debris away from the fittings on top
of the junction block.
(2) If the left rear proportioning valve is suspect,
disconnect the tube nut fitting at the primary port of
the junction block (Fig. 53). Install appropriate
Adapter, Special Tool 6833, in its place on the junc-
tion block.
(3) If the right rear proportioning valve is suspect,
disconnect the tube nut fitting at the secondary port
of the junction block (Fig. 53). Install appropriate
Adapter, Special Tool 6833, in its place on the junc-
tion block.
(4) Connect previously removed brake tube to
Adapter.
(5) Install Pressure Gauge, Special Tool C-4007-A,
to the Adapter.
(6) Tighten all tube nut fittings to 17 N·m (145 in.
lbs.) torque.
(7) Remove the chassis brake tube leading to
either the left rear or right rear brake at the junction
block (Fig. 53).
JR
BRAKES - BASE
5 - 31
POWER BRAKE BOOSTER (Continued)
(8) If the left rear proportioning valve is suspect,
install appropriate Adapter, Special Tool 6833, in the
open port for the left rear chassis tube.
(9) If the right rear proportioning valve is suspect,
instal appropriate Adapter, Special Tool 6833, in the
open port for the right rear chassis tube.
(10) Connect previously removed brake tube to
Adapter.
(11) Install Pressure Gauge, Special Tool C-4007-A,
to the Adapter.
(12) Tighten all tube nut fittings to 17 N·m (145
in. lbs.) torque.
(13) Bleed any air out of the system. This includes
bleeding the air from the hose between the pressure
test fitting and pressure gauge, which is done at the
pressure gauge.
(14) With the aid of a helper, apply pressure to the
brake pedal until reading on proportioning valve
inlet gauge (at master cylinder) is at the pressure
shown on the chart at the end of this procedure.
Then check the pressure reading on the proportion-
ing valve outlet gauge (at junction block outlet to
rear brake). If proportioning valve outlet pressure
does not agree with value shown on the chart (once
inlet pressure shown on chart is obtained), replace
the
junction
block
(with
internal
proportioning
valves) (Refer to 5 - BRAKES - BASE/HYDRAULIC/
MECHANICAL/JUNCTION BLOCK - REMOVAL). If
pressure is within specifications, do not replace pro-
portioning valve and perform the following steps.
(15) Remove the Pressure Gauges and Adapters
from the junction block.
(16) Reinstall the brake tubes to the junction block
ports. Tighten tube nuts fitting to 17 N·m (145 in.
lbs.) torque.
(17) Bleed the affected brake lines. (Refer to 5 -
BRAKES - BASE - STANDARD PROCEDURE)
(18) If no problem is found with the proportioning
valves, check the rear wheel brake shoe linings for
contamination or for replacement brake shoes not
meeting OEM brake lining material specifications.
These conditions can also cause premature rear
wheel skid.
PROPORTIONING VALVE SPECIFICATIONS
Vehicle
Brake System
Type
Split Point
Slope
Inlet
Pressure*
Outlet
Pressure*
JR27
Disc/Disc
400 psi
0.27
1000 psi
510-610 psi
JR41
Disc/Drum
400 psi
0.34
1000 psi
550-650 psi
JR41
Disc/Disc
350 psi
0.27
1000 psi
525-625 psi
* NOTE: Inlet and outlet pressures listed are
approximations and actual results may differ. Pres-
sures listed should be used as guidelines only.
NOTE: DaimlerChrysler reserves the right to change
values of proportioning valves used.
Fig. 53 Junction Block Fitting Identification
1 - FROM MASTER CYLINDER PRIMARY
2 - FROM MASTER CYLINDER SECONDARY
3 - TO LEFT FRONT BRAKE
4 - TO RIGHT REAR BRAKE
5 - TO LEFT REAR BRAKE
6 - TO RIGHT FRONT BRAKE
5 - 32
BRAKES - BASE
JR
PROPORTIONING VALVE (Continued)
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. For information on
brake rotor machining, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS
-
STANDARD
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. 54). Limits can also
be found in the table at the end of this brake rotor
information.
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. 55). If thickness measurements vary by
more than 0.013 mm (0.0005 inch), the rotor should
refaced or replaced. For information on brake rotor
machining, (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/ROTORS - STANDARD PROCEDURE).
Fig. 54 Minimum Thickness Markings (Typical)
1 - ROTOR MINIMUM THICKNESS MARKING
2 - ROTOR
Fig. 55 Checking Rotor For Thickness
1 - MICROMETER
JR
BRAKES - BASE
5 - 33
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
25 mm (one inch) from outer edge of rotor (Fig. 56).
Check lateral runout on both sides of the rotor,
marking the low and high spots on both. Runout lim-
its can be found in the table at the end of this brake
rotor information.
If runout is in excess of the specification, check the
lateral runout of the hub face. Before removing the
rotor from the hub, place a chalk mark across both
the rotor and the one wheel stud closest to where the
high runout measurement was taken. This way, the
original mounting spot of the rotor on the hub is
indexed (Fig. 57).
Remove the rotor from the hub.
NOTE: Clean the hub face surface before checking
runout. This provides a clean surface to get an
accurate indicator reading.
Mount Dial Indicator, Special Tool C-3339, and
Mounting Adaptor, Special Tool SP-1910, to the steer-
ing knuckle. Position the indicator stem so it contacts
the hub face near the outer diameter. Care must be
taken to position stem outside of the stud circle, but
inside of the chamfer on the hub rim (Fig. 58).
Fig. 56 Checking Rotor Runout
1 - SPECIAL TOOL SP-1910
2 - 25 mm FROM EDGE
3 - DISC SURFACE
4 - SPECIAL TOOL C-3339
Fig. 57 Marking Rotor and Wheel Stud
1 - CHALK MARK
Fig. 58 Checking Hub Runout
1 - HUB SURFACE
2 - SPECIAL TOOL C-3339
3 - SPECIAL TOOL SP-1910
5 - 34
BRAKES - BASE
JR
ROTOR (Continued)
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