2000 DODGE NEON Service Repair Manual

DESCRIPTION AND OPERATION
BASE BRAKE SYSTEM OPERATION
When a vehicle needs to be stopped, the driver
applies the brake pedal. The brake pedal pushes the
input rod of the power brake booster into the booster.
The booster uses vacuum to ease pedal effort as force
is transferred through the booster to the master cyl-
inder. The booster's output rod pushes in the master
cylinder's primary and secondary pistons applying
hydraulic pressure through the chassis brake tubes
and proportioning valves (rear only) to the brakes at
each tire and wheel assembly.
Front disc brakes control the braking of the front
wheels; rear braking is controlled by rear drum
brakes as standard equipment. Rear disc brakes and
an antilock brake system (ABS) with traction control
are optional.
The hydraulic brake system is diagonally split on
both the non-antilock and antilock braking systems.
This means the left front and right rear brakes are
on one hydraulic circuit and the right front and left
rear are on the other.
Vehicles equipped with the optional antilock brake
system (ABS) use a system designated Mark 20e.
This system shares most base brake hardware used
on vehicles without ABS. A vehicle equipped with
ABS, however, uses a different master cylinder and
brake tubes. Also included in the ABS system is an
integrated control unit (ICU) and four wheel speed
sensors. These components are described in detail in
the ANTILOCK BRAKE SYSTEM section in this
group of the service manual. All vehicles with ABS
come standard with four-wheel-disc brakes and trac-
tion control.
The parking brakes are hand-operated. When
applied, the parking brake lever pulls on cables that
actuate brake shoes at each rear wheel. The parking
brake lever has an automatic adjusting feature that
takes up any excessive slack in the parking brake
cable system.
BASE BRAKE SYSTEM COMPONENTS
BRAKE PEDAL
A suspended-type brake pedal is used on this vehi-
cle. The pedal pivots on a shaft mounted in the pedal
support bracket under the instrument panel. The
pedal connects to the power brake booster input rod
and pushes it in when the pedal is applied.
The brake pedal and it's pad are serviceable sepa-
rately.
POWER BRAKE BOOSTER
There are two different power brake booster
designs, although externally they appear the same.
All vehicles use a 205 mm tandem diaphragm power
brake booster. The two boosters are internally tuned
differently depending on whether the vehicle is
equipped with the standard front disc/rear drum
brake combination or the optional front disc/rear disc
(four-wheel disc) brake combination. If the power
brake booster requires replacement, be sure it is
replaced with the correct part.
The power brake booster can be identified by the
tag attached to the body of the booster assembly (Fig.
1). This tag contains the following information: The
production part number of the power brake booster,
the date it was built and who manufactured it.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop the vehicle.
The power brake booster is vacuum-operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 2).
As the brake pedal is depressed, the power booster
input rod moves forward. This opens and closes
valves in the power brake booster, allowing atmo-
spheric pressure to enter on one side of a diaphragm.
Engine vacuum is always present on the other side.
This difference in pressure forces the output rod of
the power booster out against the primary piston of
the master cylinder. As the pistons in the master cyl-
inder move forward, hydraulic pressure is created in
the brake system.
Fig. 1 Master Cylinder and Power Brake Booster
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
5 - 2 BRAKESPL

The power brake vacuum booster assembly mounts
on the engine side of the dash panel. The booster
input push rod connects to the brake pedal. A vac-
uum line connects the power booster to the intake
manifold. The master cylinder is bolted to the front
of the power brake booster.
MASTER CYLINDER
The base brakes on a vehicle not equipped with
ABS use a standard compensating port master cylin-
der, while vehicles equipped with ABS use a center
valve design master cylinder. The information pro-
vided here applies only to the non-ABS master cylin-
der. For information on the master cylinder used on
vehicles with ABS, refer to the ANTILOCK BRAKE
SYSTEM section in this service manual group.
The non-ABS master cylinder is a four-outlet
design with two screw-in proportioning valves. One is
attached directly to the inboard side of the master
cylinder housing while the other is attached to the
bottom (Fig. 3). Vehicles equipped with rear drum
brakes use a master cylinder with a 22.23 mm (0.875
in.) bore diameter, while vehicles equipped with rear
disc brakes use a 23.82 mm (0.937 in.) bore diameter
master cylinder.
The master cylinder body is an anodized aluminum
casting. It has a machined bore to accept the master
cylinder piston and also has threaded ports with
seats for hydraulic brake line connections.
The master cylinder's primary outlet ports supply
hydraulic pressure to the right front and left rearbrakes while the secondary outlet ports supply
hydraulic pressure to the left front and right rear
brakes (Fig. 3).
BRAKE FLUID RESERVOIR
The master cylinder has the brake fluid reservoir
mounted on top of it which gravity feeds brake fluid
to the master cylinder when it is required. The res-
ervoir is made of see-through plastic and it houses
the brake fluid level switch.
BRAKE FLUID LEVEL SWITCH
The brake fluid level switch is located in the brake
fluid reservoir on the master cylinder (Fig. 1). It
senses the level of the brake fluid within the reser-
voir and when the level drops below an acceptable
level, the switch closes and completes the ground cir-
cuit for the red BRAKE warning lamp. This turns on
the red BRAKE warning lamp. For additional infor-
mation, refer to RED BRAKE WARNING LAMP also
in this section.
PROPORTIONING VALVE
NOTE: Only vehicles without antilock brakes have
proportioning valves. Vehicles with antilock brakes
have electronic brake distribution that is built into
the integrated control unit.
Fig. 2 Power Brake Booster
1 ± MOUNTING STUD
2 ± PARTS IDENTIFICATION TAG
3 ± MASTER CYLINDER MOUNTING STUDS
4 ± VACUUM CHECK VALVE
Fig. 3 Non-ABS 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
PLBRAKES 5 - 3
DESCRIPTION AND OPERATION (Continued)

Proportioning valves balance front to rear braking
by controlling the brake fluid hydraulic pressure to
the rear brakes. Under light pedal application, the
proportioning valve allows normal fluid flow to the
rear brakes. Under higher pedal effort, the valve
reduces fluid pressure to the rear brakes.
The non-antilock master cylinder is a four-outlet
design with two screw-in proportioning valves
attached directly to the master cylinder housing (Fig.
3). One proportioning valve controls each rear brake.
BRAKE TUBES AND HOSES
The purpose of the brake tubes and flex hoses is to
transfer the pressurized brake fluid developed by the
master cylinder to the brakes at each wheel of the
vehicle. The flex hoses connect the chassis brake
tubes, which are mounted to the vehicle's underbody,
to the brake at each wheel, allowing for movement of
the vehicle's suspension. The brake tubes are steel
with a corrosion-resistant nylon coating applied to
the external surfaces. The flex hoses are made of
reinforced rubber.
DISC BRAKES (FRONT)
The front disc brakes consist of the following com-
ponents (Fig. 4):
²Brake caliper - single-piston, floating type
²Brake shoes and linings
²Brake rotorWhen the brakes are applied, fluid pressure is sent
to each brake caliper. The pressure at the caliper is
exerted equally against the caliper piston. The pres-
sure applied to the piston is transmitted directly to
the inboard brake shoe. This forces the shoe lining
against the inner surface of the brake rotor. At the
same time, fluid pressure within the caliper piston
bore forces the caliper to slide inward on its guide
pins. This action brings the outboard shoe lining into
contact with the outer surface of the brake rotor.
This pressure on both sides of the brake rotor causes
friction, bringing the vehicle to a stop.
BRAKE CALIPER
The caliper is a one-piece casting with the inboard
side containing a single piston cylinder bore (Fig. 5).
The front disc brake caliper piston, is manufac-
tured from a phenolic compound. The outside diame-
ter of the caliper piston is 54 mm.
A square-cut rubber piston seal is located in a
machined groove in the caliper cylinder bore. This
provides a hydraulic seal between the piston and the
cylinder wall (Fig. 6). The piston seal is designed to
pull the piston back into the bore of the caliper when
the brake pedal is released. This maintains the
proper brake shoe-to-rotor clearance.
A rubber dust boot is installed in the cylinder bore
opening and in a groove in the piston (Fig. 6). This
prevents contamination in the bore area.
The caliper is mounted to the steering knuckle
using bushings, sleeves and two guide pin bolts (Fig.
5). The guide pin bolts thread directly into bosses on
the steering knuckle.
Two machined abutments on the steering knuckle
position the caliper. The guide pin bolts, sleeves, and
bushings control the side-to-side movement of the
caliper. All of the front brake force generated during
braking of the vehicle is taken up directly by the
steering knuckles of the vehicle.
BRAKE SHOES AND LININGS
There are two brake shoes mounted to each caliper,
one inboard and one outboard (Fig. 5). When brake
shoes are replaced, only brake shoes meeting the
original equipment manufacturer (OEM) formulation
(such as Mopartreplacement parts) should be used.
As front disc brake shoe linings wear, master cyl-
inder reservoir brake fluid level will drop. Fluid level
should be checked after replacing shoes.
Front disc brakes are equipped with an audible
wear indicator on the outboard brake pad (Fig. 5).
This sensor emits a sound when the brake lining
may need inspection or replacement.
Fig. 4 Front Disc Brakes
1 ± STEERING KNUCKLE
2 ± BRAKE PADS AND LININGS
3 ± BRAKE ROTOR
4 ± DRIVING HUB
5 ± CALIPER ASSEMBLY
5 - 4 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

BRAKE ROTOR
The brake shoe linings contact the brake rotor.
Each front brake rotor is vented to help cool it during
and after brake applications. It is mounted on the
studs of the front wheel bearing hub.
DRUM BRAKES (REAR)
Rear drum brakes are standard equipment on this
vehicle. The rear drum brakes consist of the major
components listed in the figure (Fig. 7). Other com-
ponents related to the brake shoes themselves can be
seen in the next figure (Fig. 8).
The rear wheel drum brakes are a two-shoe, inter-
nal-expanding type with an automatic adjuster screw
(Fig. 8). The automatic adjuster screw is actuated
each time the brakes are applied. The automatic
adjuster screw is located directly below the rear
brake wheel cylinder.
Fig. 5 Front Disc Brake Caliper
1 ± CALIPER GUIDE PIN BOLT
2 ± SLEEVE
3 ± BUSHING
4 ± CALIPER
5 ± PISTON SEAL
6 ± PISTON
7 ± DUST SEAL
8 ± WEAR INDICATOR
9 ± ANTI-RATTLE CLIP10 ± BRAKE SHOE
11 ± BRAKE SHOE
12 ± ANTI-RATTLE CLIP
13 ± BUSHING
14 ± SLEEVE
15 ± CALIPER GUIDE PIN BOLT
16 ± CAP
17 ± BLEEDER SCREW
Fig. 6 Piston Seal Function
1 ± PISTON
2 ± CYLINDER BORE
3 ± PISTON SEAL BRAKE PRESSURE OFF
4 ± CALIPER HOUSING
5 ± DUST BOOT
6 ± PISTON SEAL BRAKE PRESSURE ON
PLBRAKES 5 - 5
DESCRIPTION AND OPERATION (Continued)

DISC BRAKES (REAR)
Rear disc brakes are optional equipment on some
models of this vehicle (Fig. 9). The rear disc brakes
are similar to the front disc brakes; however, there
are several distinctive features that require different
service procedures. The rear disc brakes consist of
the following components:
²Brake caliper - single-piston, floating type
²Brake caliper adapter
²Brake shoe and linings
²Brake rotor - drum-in-hat type
All vehicles equipped with rear disc brakes have a
small duo-servo drum brake mounted to the caliper
adapter. This is part of the parking brake system.
The drum brake shoes expand out against a braking
surface (hat section) on the inside area of the disc
brake rotor.
BRAKE CALIPER
Vehicles are equipped with a caliper assembly that
has a 34 mm (1.43 in.) piston and uses a solid non-
vented rotor.
The caliper assembly for all applications floats on
rubber bushings using internal metal sleeves that
are attached to the adapter using threaded guide pin
bolts.
BRAKE CALIPER ADAPTER
The brake caliper adapter and rotor shield are
mounted to the rear suspension knuckles of vehicle.
Fig. 7 Rear Drum Brakes
1 ± DUST CAP
2 ± NUT
3 ± DRUM
4 ± HUB AND BEARING
5 ± WHEEL CYLINDER
6 ± SEAL
7 ± SUPPORT PLATE
8 ± BRAKE SHOES
9 ± RETAINER CLIP
Fig. 8 Drum Brake Shoes (Left Side Shown)
1 ± WHEEL CYLINDER
2 ± AUTOMATIC ADJUSTER SCREW ASSEMBLY
3 ± RETURN SPRING
4 ± HOLD DOWN CLIP
5 ± HOLD DOWN CLIP
6 ± AUTOMATIC ADJUSTER LEVER AND SPRING
7 ± PARK BRAKE LEVER
8 ± PARK BRAKE CABLE
9 ± FRONT BRAKE SHOE
10 ± BRAKE SHOE TO ANCHOR SPRING
11 ± BRAKE ANCHOR PLATE
12 ± REAR BRAKE SHOE
Fig. 9 Rear Disc Brakes
1 ± DISC BRAKE CALIPER
2 ± DISC BRAKE ADAPTER
3 ± GUIDE PIN BOLTS
4 ± HUB AND BEARING
5 ± BRAKE ROTOR
6 ± RETAINER CLIP
7 ± DUST CAP
8 ± NUT
5 - 6 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

The adapter is used to mount the brake caliper to the
vehicle (Fig. 9). The adapter has two machined abut-
ments, which are used to position and align the cal-
iper and brake pads for movement inboard and
outboard. The adapter also mounts the parking brake
shoes and actuating cables to the vehicle.
PARKING BRAKES
The parking brakes (Fig. 4) consist of the following
components:
²Hand-operated park brake lever - automatic-ad-
justing
²Parking brake cables
²Actuation levers and struts
²Duo-servo parking brake assembly (rear disc
only)
PARKING BRAKE LEVER
All vehicles are equipped with a center-mounted,
hand-operated parking brake lever mounted between
the front seats (Fig. 10). This lever is an automatic-
adjusting type that continuously applies minimal
tension to the parking brake cables to keep them in
adjustment at all times. Due to this feature, the
parking brake cable system does not require adjust-
ment. Proper parking brake system adjustment is
obtained by proper drum brake or drum-in-hat brake
shoe adjustment. When service is needed, the lever
auto-adjust mechanism must be reloaded and locked
out before service can be performed.
The parking brake lever has a short output cable
with an equalizer bracket attached to it that connects
to the parking brake cables (Fig. 10). The output
cable can only be serviced as part of the parking
brake lever.PARKING BRAKE CABLES
There is an individual parking brake cable for each
rear wheel that joins a parking cable equalizer,
attached to the parking brake lever, to the rear park-
ing brakes. The parking brake cables are made of
flexible steel cable. Both drum rear brakes and disc
rear brakes use the same parking brake cable config-
uration, but the cables are different.
PARKING BRAKES
On vehicles equipped with rear drum brakes, the
rear wheel service brakes also act as the vehicle's
parking brakes. The rear drum brake shoes, when
acting as parking brakes, are mechanically operated
using an internal actuating lever and strut connected
to the flexible steel parking brake cable.
The parking brakes on vehicles equipped with rear
disc brakes consist of a small duo-servo brake assem-
bly mounted to the disc brake caliper adapter (Fig.
11). The hat (center) section of the rear brake rotor
serves as the braking surface (drum) for the parking
brakes (Fig. 12). This parking brake application uses
the same operating cable configuration as the drum
brake equipped vehicles, but different cables.
Fig. 10 Parking Brake Lever
1 ± PARKING BRAKE LEVER
2 ± PARKING BRAKE WARNING LAMP SWITCH
3 ± OUTPUT CABLEFig. 11 Parking Brake Assembly With Rear Disc
Brakes
1 ± DISC BRAKE ADAPTER
2 ± PARKING BRAKE BRAKE SHOES
3 ± HUB/BEARING ASSEMBLY
4 ± BRAKING DISC STONE SHIELD
5 ± PARKING BRAKE ACTUATING STRUT
PLBRAKES 5 - 7
DESCRIPTION AND OPERATION (Continued)

RED BRAKE WARNING LAMP
The red BRAKE warning lamp is located in the
instrument panel cluster and illuminates when a low
brake fluid condition occurs or when the parking
brake lever is applied with the ignition key in the
ON position. In addition, the red BRAKE warning
lamp illuminates when the ignition switch is moved
from the OFF to the ON or CRANK position. This is
done to check the bulb's operation.
Problems with this system will generally be of the
type where the warning lamp fails to turn on when it
should, or remains on when it should not.
The red BRAKE warning lamp LED is supplied
with current anytime the ignition switch is ON. The
bulb is illuminated by completing the ground circuit
using any of the following components:
²the brake fluid level switch located in the mas-
ter cylinder reservoir
²the parking brake switch mounted on the park-
ing brake lever (Fig. 10)
²the ignition switch when the ignition switch is
first moved to the ON or CRANK position
²the mechanical instrument cluster (MIC) (with
ABS)
²the ABS electronic brake distribution (EBD)
The brake fluid level switch is located in the brake
fluid reservoir of the master cylinder assembly (Fig.
1). The purpose of the switch is to provide the driver
with an early warning that the brake fluid level inthe master cylinder reservoir has dropped below an
acceptable level.
As the fluid drops below the minimum level, the
fluid level switch closes and grounds the red BRAKE
warning lamp circuit. This turns on the red BRAKE
warning lamp. At this time, the master cylinder fluid
reservoir must be checked and filled to the full mark
with DOT 3 brake fluid. An abnormal loss of brake
fluid in the master cylinder fluid reservoir could be
caused by a leak in the hydraulic system. The entire
brake hydraulic system should be checked for evi-
dence of a leak.
The red BRAKE warning lamp can be turned on by
the MIC in the case where the ABS is experiencing a
problem where the amber ABS warning lamp needs
to be illuminated and cannot. The MIC will then illu-
minate the red BRAKE warning lamp.
BRAKE LAMP SWITCH
The brake lamp switch is located under the instru-
ment panel, at the brake pedal arm (Fig. 13). It con-
trols operation of the vehicle's stop lamps. Also, if the
vehicle is equipped with speed control, the brake
lamp switch will deactivate the speed control when
the brake pedal is depressed.
When the brake pedal is depressed, the brake lamp
switch contacts are closed, completing the circuit to
the stop lamps, thus illuminating the stop lamps and
the center-high-mounted stop lamp (CHMSL).
Fig. 12 Drum-In-Hat Brake Rotor
1 ± REAR BRAKING DISK ROTOR
2 ± HAT SECTION OF REAR BRAKING DISC (PARKING BRAKE
BRAKING SURFACE)
Fig. 13 Brake Lamp Switch
1 ± SWITCH
2 ± CLIP
3 ± BRAKE PEDAL
4 ± CONNECTOR
5 - 8 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

DIAGNOSIS AND TESTING
BASE BRAKE SYSTEM DIAGNOSIS CHARTS
NOTE: There are three diagnosis charts following
that cover the RED BRAKE WARNING LAMP,
BRAKE NOISE and OTHER BRAKE CONDITIONS.
RED BRAKE WARNING LAMP
CONDITION POSSIBLE CAUSES CORRECTION
RED BRAKE WARNING
LAMP ON1. Parking brake lever not fully
released.1. Release parking brake lever.
2. Parking brake warning lamp switch
on parking brake lever.2. Inspect and replace switch as necessary.
3. Brake fluid level low in reservoir. 3. Fill reservoir. Check entire system for
leaks. Repair or replace as required.
4. Brake fluid level switch. 4. Disconnect switch wiring connector. If lamp
goes out, replace switch.
5. Mechanical instrument cluster (MIC)
problem.5. Refer to Chassis Diagnostic Procedures
manual.
6. ABS EBD malfunction. 6. Refer to ABS section and Chassis
Diagnostic Procedures manual.
BRAKE NOISE
CONDITION POSSIBLE CAUSES CORRECTION
DISC BRAKE CHIRP 1. Excessive brake rotor runout. 1. Follow brake rotor diagnosis and testing.
Correct as necessary.
2. Lack of lubricant on brake caliper
slides.2. Lubricate brake caliper slides.
DISC BRAKE RATTLE OR
CLUNK1. Broken or missing anti-rattle spring
clips on shoes.1. Replace brake shoes.
2. Caliper guide pins loose. 2. Tighten guide pins.
DISC BRAKE SQUEAK AT
LOW SPEED (WHILE
APPLYING LIGHT BRAKE
PEDAL EFFORT)1. Brake shoe linings. 1. Replace brake shoes.
DRUM BRAKE CHIRP 1. Lack of lubricant on brake shoe
support plate where shoes ride.1. Lubricate shoe contact areas on brake
shoe support plates.
2. Wheel cylinder out of alignment. 2. Loosen wheel cylinder mounting bolts,
realign wheel cylinder with brake shoes and
tighten mounting bolts.
DRUM BRAKE CLUNK 1. Drum(s) have threaded machined
braking surface.1. Reface or replace drake drums as
necessary.
DRUM BRAKE HOWL OR
MOAN1. Lack of lubricant on brake shoe
support plate where shoes ride and at
the anchor.1. Lubricate shoe contact areas on brake
shoe support plates and at the anchor.
2. Rear brake shoes. 2. Replace rear brake shoes.
DRUM BRAKE SCRAPING
OR WHIRRING1. ABS wheel speed sensor or tone
wheel.1. Inspect, correct or replace faulty
component(s).
SCRAPING (METAL-TO-
METAL).1. Foreign object interference with
brakes.1. Inspect brakes and remove foreign object.
2. Brake shoes worn out. 2. Replace brake shoes. Inspect rotors and
drums. Reface or replace as necessary.
PLBRAKES 5 - 9