2000 DODGE NEON Service Repair Manual

OTHER BRAKE CONDITIONS
CONDITION POSSIBLE CAUSES CORRECTION
BRAKES CHATTER 1. Rear brake drum out of round or
disc brake rotor has excessive
thickness variation.1. Isolate condition as rear or front.
Reface or replace brake drums or rotors
as necessary.
BRAKES DRAG (FRONT OR
ALL)1. Contaminated brake fluid. 1. Check for swollen seals. Replace all
system components containing rubber.
2. Binding caliper pins or bushings. 2. Replace pins and bushings
3. Binding master cylinder. 3. Replace master cylinder.
4. Binding brake pedal. 4. Replace brake pedal.
BRAKES DRAG (REAR
ONLY)1. Parking brake cables binding or
froze up.1. Check cable routing. Replace cables as
necessary.
2. Parking brake cable return spring
not returning shoes.2. Replace cables as necessary.
3. Service brakes not adjusted properly
(rear drum brakes only).3. Follow the procedure listed in the
adjustment section.
4. Obstruction inside the center
console preventing full return of the
parking brake cables.4. Remove console and remove
obstruction.
BRAKES GRAB 1. Contaminated brake shoe linings. 1. Inspect and clean, or replace shoes.
Repair source of contamination.
2. Improper power brake booster
assist.2. Refer to power brake booster in the
diagnosis and testing section.
EXCESSIVE PEDAL
EFFORT1. Obstruction of brake pedal. 1. Inspect, remove or move obstruction.
2. Low power brake booster assist. 2. Refer to power brake booster in the
diagnosis and testing section.
3. Glazed brake linings. 3. Reface or replace brake rotors as
necessary. Replace brake shoes.
4. Brake shoe lining transfer to brake
rotor.4. Reface or replace brake rotors as
necessary. Replace brake shoes.
EXCESSIVE PEDAL
TRAVEL (VEHICLE STOPS
OK)1. Air in brake lines. 1. Bleed brakes.
2. Rear drum brake auto-adjuster
malfunctioning.2. Inspect and replace drum brake
components as necessary. Adjust rear
brakes.
EXCESSIVE PEDAL
TRAVEL (PEDAL GOES TO
FLOOR - CAN'T SKID
WHEELS)1. Power brake booster runout
(vacuum assist).1. Check booster vacuum hose and
engine tune for adequate vacuum supply.
Refer to power brake booster in the
diagnosis and testing section.
EXCESSIVE PEDAL
TRAVEL (ONE FRONT
WHEEL LOCKS UP DURING
HARD BRAKING)1. One of the two hydraulic circuits to
the front brakes is malfunctioning.1. Inspect system for leaks. Check master
cylinder for internal malfunction.
5 - 10 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
PEDAL PULSATES/SURGES
DURING BRAKING1. Rear brake drum out of round or
disc brake rotor has excessive
thickness variation.1. Isolate condition as rear or front.
Reface or replace brake drums or rotors
as necessary.
PEDAL IS SPONGY 1. Air in brake lines. 1. Bleed brakes.
2. Power brake booster runout
(vacuum assist).2. Check booster vacuum hose and
engine tune for adequate vacuum supply.
Refer to power brake booster in the
diagnosis and testing section.
PREMATURE REAR WHEEL
LOCKUP1. Contaminated brake shoe linings. 1. Inspect and clean, or replace shoes.
Repair source of contamination.
2. Inoperative proportioning valve
(non-ABS vehicles only).2. Test proportioning valves folowing
procedure listed in diagnosis and testing
section. Replace valves as necessary.
3. ABS EBD not functioning. 3. Refer to the ABS section and Chassis
Diagnostic Procedures manual.
4. Improper power brake booster
assist.4. Refer to power brake booster in the
diagnosis and testing section.
STOP LAMPS STAY ON 1. Brake lamp switch out of
adjustment.1. Adjust brake lamp switch.
2. Brake pedal binding. 2. Inspect and replace as necessary.
3. Obstruction in pedal linkage. 3. Remove obstruction.
4. Power Brake Booster not allowing
pedal to return completely.4. Replace power brake booster.
VEHICLE PULLS TO RIGHT
OR LEFT ON BRAKING1. Frozen brake caliper piston. 1. Replace frozen piston or caliper. Bleed
brakes.
2. Contaminated brake shoe lining. 2. Inspect and clean, or replace shoes.
Repair source of contamination.
3. Pinched brake lines. 3. Replace pinched line.
4. Leaking piston seal. 4. Replace piston seal or brake caliper.
5. Suspension problem. 5. Refer to the Suspension group.
PARKING BRAKE -
EXCESSIVE HANDLE
TRAVEL1. Rear brakes out of adjustment. 1. Adjust rear drum brake shoes, or rear
parking brake shoes on vehicles with rear
disc brakes.
POWER BRAKE BOOSTER
BASIC TEST
(1) With engine off, depress and release the brake
pedal several times to purge all vacuum from the
power brake booster.
(2) Depress and hold the pedal with light effort (15
to 25 lbs. pressure), then start the engine.
The pedal should fall slightly, then hold. Less effort
should be needed to apply the pedal at this time. If
the pedal fell as indicated, perform the VACUUM
LEAK TEST listed after the BASIC TEST. If thepedal did not fall, continue on with this BASIC
TEST.
(3) Disconnect the vacuum hose on the side of the
vacuum check valve that leads to the speed control,
then connect a vacuum gauge to the open vacuum
port on the valve.
(4) Start the engine.
(5) When the engine is at warm operating temper-
ature, allow it to idle and check the vacuum at the
gauge.
PLBRAKES 5 - 11
DIAGNOSIS AND TESTING (Continued)

If the vacuum supply is 12 inches Hg (40.5 kPa) or
more, the power brake booster is defective and must
be replaced. If the vacuum supply is below 12 inches,
continue on with this BASIC TEST.
(6) Shut off the engine.
(7) Connect the vacuum gauge to the vacuum ref-
erence port on the engine intake manifold.
(8)
Start the engine and observe the vacuum gauge.
If the vacuum is still low, check the engine tune
and repair as necessary. If the vacuum is above 12
inches, the hose or check to the booster has a restric-
tion or leak.
Once an adequate vacuum supply is obtained,
repeat the BASIC TEST.
VACUUM LEAK TEST
(1) Disconnect the vacuum hose on the side of the
power brake booster vacuum check valve that leads
to the speed control, then connect a vacuum gauge to
the open vacuum port on the valve.
(2) Remove the remaining hose on the vacuum
check valve that is not the vacuum supply hose com-
ing from the intake manifold. Cap off the open port
on the check valve.
(3) Start the engine.
(4) Allow the engine to warm up to normal operat-
ing temperature and engine idle.
(5) Using vacuum line pliers, close off the vacuum
supply hose near the booster and observe the vacuum
gauge.
If the vacuum drop exceeds 1.0 inch Hg (3.3 kPa)
in one minute, repeat the above steps to confirm the
reading. The vacuum loss should be less than 1.0
inch Hg in one minute time span. If the loss is more
than 1.0 inch Hg, replace the power brake booster. If
it is not, continue on with this test.
(6) Remove the pliers from the hose temporarily.
(7) Apply light effort (approximately 15 lbs. of
force) to the brake pedal and hold the pedal steady.
Do not move the pedal once the pressure is applied
or the test results may vary.
(8) Have an assistant reattach the pliers to the
vacuum supply hose.
(9) Allow 5 seconds for stabilization, then observe
the vacuum gauge.
If the vacuum drop exceeds 3.0 inches Hg (10 kPa)
in 15 seconds, repeat the above steps to confirm the
reading. The vacuum loss should be less than 3.0
inches Hg in 15 seconds time span. If the loss is
more than 3.0 inches Hg, replace the power brake
booster. If it is not, the booster is not defective.
DRUM BRAKE AUTOMATIC ADJUSTER
To properly test the drum brake automatic
adjuster, the aide of a helper inside the vehicle to
apply the brakes will be necessary.(1) Raise the vehicle. Refer to HOISTING in the
LUBRICATION AND MAINTENANCE group for the
proper lifting procedure.
(2) Remove the access plug from the rear adjust-
ment slot in each brake support plate.
(3) Insert a thin screwdriver in the adjustment
slot and push back the adjustment lever. With the
lever in this position, back the star wheel adjustment
off approximately 10 notches. This will eliminate the
possibility that the brake is at full adjustment, and
can be adjusted no further.
(4)
Remove the screwdriver from the adjustment slot.
(5) Watch the star wheel through the adjustment
slot, while a helper applies the brake pedal. As the
brake shoes apply, the adjustment lever should move
downward, turning the star wheel. A definite rotation
of the adjuster star wheel can be observed if the
automatic adjuster is working properly.
If the star wheel does not move as indicated, the
brake drum needs to be removed and further inspec-
tion of the rear brakes is necessary.
(6) If the star wheel is operating properly, readjust
the brakes. Refer to ADJUSTMENTS in this section
of this service manual group.
(7) Reinstall the adjustment slot access plug.
(8) Lower the vehicle.
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. Refer to SERVICE PRO-
CEDURES in this section of this group for informa-
tion on brake rotor machining.
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.
5 - 12 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

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. 14). 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. 15). If thickness measurements vary by
more than 0.013 mm (0.0005 inch), the rotor should
refaced or replaced. Refer to SERVICE PROCE-
DURES in this section of this group for information
on brake rotor machining.
ROTOR RUNOUT
On-vehicle rotor runout is the combination of the
individual runout of the hub face and the runout ofthe 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 one
inch from edge of rotor (Fig. 16). Check lateral runout
on both sides of the rotor, marking the low and high
spots on both. Runout limits 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. 17).
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. 18).
Fig. 14 Minimum Brake Rotor Thickness Markings
(Typical)
1 ± ROTOR MINIMUM THICKNESS MARKING
2 ± ROTOR
Fig. 15 Checking Rotor For Thickness
1 ± CALIPER
PLBRAKES 5 - 13
DIAGNOSIS AND TESTING (Continued)

Hub runout should not exceed 0.08 mm (0.003
inch). If runout exceeds this specification, the hub
must be replaced. Refer to the SUSPENSION group
in this service manual for the replacement procedure.
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. 19).
Tighten nuts in the proper sequence and torque to
specifications.
Recheck brake rotor runout to see if the runout is
now within specifications.If runout is not within specifications, reface or
replace the brake rotor. Refer to SERVICE PROCE-
DURES in this section of this group for information
on brake rotor machining.
Fig. 16 Checking Rotor Runout
1 ± SPECIAL TOOL SP-1910
2 ± 10 MILLIMETERS FROM EDGE
3 ± DISC SURFACE
4 ± SPECIAL TOOL C-3339
Fig. 17 Marking Rotor and Wheel Stud
1 ± CHALK MARK
Fig. 18 Checking Hub Runout
1 ± HUB SURFACE
2 ± SPECIAL TOOL C-3339
3 ± SPECIAL TOOL SP-1910
Fig. 19 Index Rotor And Wheel Stud
1 ± CHALK MARK
5 - 14 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

BRAKE ROTOR LIMITS
Braking Rotor Rotor ThicknessMinimum
Rotor
ThicknessRotor
Thickness
VariationRotor
Runout*Rotor Micro
Finish
Front Rotor21.87±22.13 mm
0.861-0.871 in.20.4 mm
0.803 in.0.013 mm
0.0005 in.0.13 mm
0.005 in.15-80 RMS
Rear Rotor8.75±9.25 mm
0.344 -0.364 in.7.25 mm
0.285 in.0.013 mm
0.0005 in.0.13 mm
0.005 in.15-80 RMS
* TIR Total Indicator Reading (Measured On Vehicle)
BRAKE DRUM
With the drum off the vehicle, measure the drum
for diameter variation (oval shape). The diameter
variation of the drum braking surface must not
exceed either 0.0635 mm (0.0025 inch) in 30É or
0.0889 mm (0.0035 inch) in 360É.
Measure brake drum runout. Brake drum runout
should be checked with the drum mounted on a
brake lathe. Brake drum runout should not exceed
0.1524 mm (0.006 inch).
If either of these measurements are not within
specification, reface or replace the drum. Refer to
BRAKE DRUM MACHINING in the SERVICE PRO-
CEDURES section of this service manual group for
refacing procedures.
Always replace the drum if machining will cause
the diameter to exceed drum maximum diameter. All
brake drums are marked with the maximum allow-
able brake drum diameter (Fig. 20).
PROPORTIONING VALVE
If premature rear wheel skid occurs on a hard
brake application, it could be an indication that a
malfunction has occurred with one of the proportion-
ing valves.
One proportioning valve controls the right rear
brake, and the other proportioning valve controls the
left rear brake (Fig. 21). Therefore, a road test to
determine which rear brake skids first is essential.
Before testing the proportioning valve in question,
inspect the rear brake linings for contamination or
for replacement shoes not meeting the OEM brake
lining material specifications.
The proportioning valve should always be tested
prior to being replaced.
Fig. 20 Brake Drum Maximum Diameter
Identification
1 ± HUB/BEARING ASSEMBLY
2 ± WHEEL MOUNTING STUDS
3 ± BRAKE DRUM MAXIMUM DIAMETER MARKING
4 ± REAR BRAKE DRUM
Fig. 21 Proportioning Valve Location
1 ± RIGHT FRONT BRAKE TUBE
2 ± LEFT FRONT BRAKE TUBE
3 ± LEFT REAR BRAKE TUBE
4 ± REAR PROPORTIONING VALVES
5 ± RIGHT REAR BRAKE TUBE
PLBRAKES 5 - 15
DIAGNOSIS AND TESTING (Continued)

The in-line proportioning valves used on this vehi-
cle require special pressure fittings to test the pro-
portioning valves for proper proportioning valve
function. The pressure fittings are installed before
and after the proportioning valve being tested to ver-
ify proportioning valve is maintaining the required
hydraulic pressure to the rear wheel brake which it
controls.
The testing of proportioning valves for this vehicle,
if equipped with ABS, can be found in the
ANTILOCK BRAKE SYSTEM section.
PROPORTIONING VALVE TEST
The test procedure is the same for either rear pro-
portioning valve. After road testing the vehicle to
determine which wheel skids first, follow the proce-
dure below for testing the suspect proportioning
valve.
(1) Using a brake pedal holding tool as shown (Fig.
22), depress the brake pedal past its first one inch of
travel and hold it in this position. This will isolate
the master cylinder from the brake hydraulic system
and will not allow the brake fluid to drain out of the
master cylinder reservoir.
(2) Use the figure shown to determine which pro-
portioning valve needs to be tested (Fig. 21).
(3) Remove the hydraulic brake tube from the pro-
portioning valve controlling the rear wheel of the
vehicle that has premature wheel skid.
(4) Remove the proportioning valve from its outlet
port on the master cylinder.CAUTION: Be sure the pressure test fittings being
installed into master cylinder and proportioning
valve, have the correct thread sizes needed.
(5) Install the Brake Pressure Adapters, Special
Tool 8644 and 6805-3 onto the proportioning valve
(Fig. 23).
(6) Install the proportioning valve (with tools) back
into the outlet port on the master cylinder.
(7) Attach a Pressure Gauge, Special Tool
C-4007-A, to each pressure adapter (Fig. 24).
(8) Remove the brake pedal holding tool. Bleed any
air out of the pressure gauge hoses at the pressure
gauge.
(9) With the aid of a helper, apply pressure to the
brake pedal until the reading on proportioning valve
inlet gauge is at the target inlet pressure shown in
the BRAKE PROPORTIONING VALVE APPLICA-
TIONS AND PRESSURE SPECIFICATIONS table
Fig. 22 Brake Pedal Holding Tool
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. 23 Tools On Valve
1 ± PROPORTIONING VALVE
Fig. 24 Pressure Gauge Set
1 ± SPECIAL TOOL C-4007±A
5 - 16 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

following this procedure. If the inlet gauge pressure
overshoots its target pressure when the pedal is
depressed, release the brake pedal, relieving the
pressure in the system, before reapplying the pedal
to reach the target pressure at the inlet gauge. This
is necessary to get an accurate reading of the outlet
pressure.
(10) Once inlet pressure has been achieved, check
the pressure reading on the proportioning valve out-
let gauge. If the proportioning valve outlet pressure
does not agree with value shown in the table, replace
the proportioning valve. If proportioning valve is
within pressure specifications, the valve is good and
does not require replacement.(11)Reinstall the brake holding tool on the brake
pedal and remove the test equipment from the vehicle.
(12) Remove the tools from the proportioning
valve.
(13) Install the proportioning valve in the master
cylinder and hand tighten until the proportioning
valve is fully installed and its O-ring seal is seated
into the master cylinder. Torque the proportioning
valve to 40 N´m (30 ft. lbs.).
(14) Install the brake tube on the proportioning
valve. Torque the tube nut to 17 N´m (145 in. lbs.).
(15) Bleed the affected brake line. See BASE
BRAKE BLEEDING in this section of this service
manual group.
BRAKE PROPORTIONING VALVE APPLICATIONS AND PRESSURE SPECIFICATIONS
Sales
CodeBrake System Type Split Point Slope IdentificationInlet
PressureOutlet Pressure
BRA 14º Disc/Drum 300 psi 0.34 Black Band 1000 psi 550-650 psi
BRD 14º Disc/Disc 400 psi 0.43 Bar Code Band 1000 psi 600-700 psi
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts. Swelling indicates 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 the fluid sep-
arates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If the brake fluid is contaminated, drain and thor-
oughly flush the brake system. Replace all the rubber
parts or components containing rubber coming into
contact with the brake fluid including: the master
cylinder; proportioning valves; caliper seals; wheel
cylinder seals; ABS hydraulic control unit; and all
hydraulic fluid hoses.
SERVICE PROCEDURES
BRAKE FLUID LEVEL CHECKING
Brake fluid level should be checked a minimum of
twice a year.
Master cylinder reservoirs are marked, FULL and
MIN, indicating the allowable brake fluid level range
in the master cylinder brake fluid reservoir (Fig. 25).
CAUTION: Use only MoparTbrake fluid or an equiv-
alent from a tightly sealed container. Brake fluid
must conform to DOT 3 specifications. Do not use
petroleum-based fluid because seal damage in the
brake system will result.Although there is a range, the preferred level is
FULL. If necessary, adjust the brake fluid level to
the FULL mark on the side of the master cylinder
brake fluid reservoir.
BASE BRAKE BLEEDING
NOTE: For bleeding the ABS hydraulic system,
refer to ANTILOCK BRAKE SYSTEM BLEEDING in
the ANTILOCK BRAKE SYSTEM section of this ser-
vice manual group.
Fig. 25 Master Cylinder
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
PLBRAKES 5 - 17
DIAGNOSIS AND TESTING (Continued)