Dodge Neon / Neon SRT-4. Manual — part 45
(1) Lubricate the O-ring on the proportioning
valve. Make sure the O-ring on the proportioning
valve is new.
(2) Install the proportioning valve in its master
cylinder port. Tighten the proportioning valve to a
torque of 17.5 N·m (155 in. lbs.).
(3) Connect the brake tube to the proportioning
valve (Fig. 117). Tighten the tube nut to a torque of
17 N·m (145 in. lbs.).
(4) Remove the brake pedal holder (Fig. 116).
(5) Bleed the affected brake line. (Refer to 5 -
BRAKES - STANDARD PROCEDURE).
(6) Road test the vehicle to ensure proper opera-
tion of the brakes.
ROTOR
DESCRIPTION - SRT-4
Vehicles equipped with the brake sales code BR3
(Performance
Disc/Disc
brake
combination)
use
heavier brake rotors. The BR3 front brake rotor is
approximately 6 mm thicker than the standard front
brake rotor. The BR3 rear brake rotor is approxi-
mately 3 mm thicker than the standard rear brake
rotor. The BR3 brake rotors can be easily identified
by the recessed machined area near the hub center
(Fig. 118) (Fig. 119).
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.
Fig. 116 Brake Pedal Holder
1 - CLUTCH PEDAL (IF EQUIPPED WITH MANUAL TRANSAXLE)
2 - THROTTLE PEDAL
3 - BRAKE PEDAL HOLDING TOOL
4 - STEERING WHEEL
5 - DRIVER’S SEAT
6 - BRAKE PEDAL
Fig. 117 Proportioning Valves On Master Cylinder
1 - RIGHT FRONT BRAKE TUBE
2 - LEFT FRONT BRAKE TUBE
3 - LEFT REAR BRAKE TUBE
4 - REAR PROPORTIONING VALVES
5 - RIGHT REAR BRAKE TUBE
Fig. 118 Front Brake Rotor Comparison
1 - STANDARD PL BRAKE ROTOR
2 - STANDARD ROTOR THICKNESS
21.87-22.13 MM
3 - PERFORMANCE ROTOR THICKNESS
27.91-28.10 MM
4 - PERFORMANCE BRAKE ROTOR
5 - INDENTIFYING MACHINED AREA
5 - 62
BRAKES - BASE
PL/SRT-4
PROPORTIONING VALVE (Continued)
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 to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTOR - 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 until the rust wears away.
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 (turn) 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. 120) (or stamped
into the hat section). Limits can also be found in this
section’s specification table. (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTOR - SPECIFICA-
TIONS)
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. 121). If thickness measurements vary
beyond the specification listed in the specifaction
table (Refer to 5 - BRAKES/HYDRAULIC/MECHAN-
Fig. 119 Rear Brake Rotor Comparison
1 - STANDARD PL BRAKE ROTOR
2 - STANDARD ROTOR THICKNESS
8.75-9.25 MM
3 - PERFORMANCE ROTOR THICKNESS
11.75-12.25 MM
4 - BR3 PERFORMANCE BRAKE ROTOR
5 - INDENTIFYING MACHINED AREA
Fig. 120 Minimum Brake Rotor Thickness Markings
(Typical)
1 - ROTOR MINIMUM THICKNESS MARKING
2 - ROTOR
PL/SRT-4
BRAKES - BASE
5 - 63
ROTOR (Continued)
ICAL/ROTOR - SPECIFICATIONS), the rotor should
be refaced or replaced. (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTOR
-
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 25
mm (1 inch) from edge of rotor (Fig. 122). Check lat-
eral 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)
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. 123).
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
Fig. 121 Checking Rotor Thickness
1 - MICROMETER
Fig. 122 Checking Rotor Runout
1 - SPECIAL TOOL SP-1910
2 - 25mm FROM EDGE
3 - DISC SURFACE
4 - SPECIAL TOOL C-3339
Fig. 123 Marking Rotor and Wheel Stud
1 - CHALK MARK
5 - 64
BRAKES - BASE
PL/SRT-4
ROTOR (Continued)
taken to position stem outside of the stud circle, but
inside of the chamfer on the hub rim (Fig. 124).
Hub runout should not exceed 0.08 mm (0.003
inch). If runout exceeds this specification, the hub
must be replaced. For front hub removal, (Refer to 2
- SUSPENSION/FRONT/KNUCKLE - REMOVAL).
For rear hub removal, (Refer to 2 - SUSPENSION/
REAR/HUB / BEARING - REMOVAL).
If the hub runout does not exceed this specifica-
tion, install the rotor back on the hub, aligning the
chalk marks on the rotor with a wheel mounting
stud, two studs apart from the original stud (Fig.
125). Tighten nuts in the proper sequence and torque
to specifications.
Recheck brake rotor runout to see if the runout is
now within specifications. (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTOR
-
SPECIFICA-
TIONS)
If runout is not within specifications, reface or
replace the brake rotor. (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTOR
-
STANDARD
PROCEDURE)
STANDARD PROCEDURE - BRAKE ROTOR
MACHINING
NOTE: Refacing the rotor is not required each time
the brake pads are replaced, only when the need is
foreseen.
Any servicing of the rotor requires extreme care to
maintain the rotor 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 refaced using a
hub-mounted
on-car
brake
lathe
(Fig.
126),
or
replaced.
The use of a hub-mounted on-car brake lathe is
highly recommended to eliminate the possibility of
excessive runout. It trues the brake rotor to the vehi-
cle’s hub and bearing.
Fig. 124 Checking Hub Runout
1 - HUB SURFACE
2 - SPECIAL TOOL C-3339
3 - SPECIAL TOOL SP-1910
Fig. 125 Index Rotor And Wheel Stud
1 - CHALK MARK
Fig. 126 On-Car Brake Lathe
1 - ON-CAR BRAKE LATHE
PL/SRT-4
BRAKES - BASE
5 - 65
ROTOR (Continued)
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