2000 DODGE NEON pressure

If the CAB calculates that the brake temperatures
are high, the traction control system becomes inoper-
ative until a time-out period has elapsed. During this
ªthermo-protection mode,º the traction control func-
tion lamp illuminates TRAC OFF; note that no trou-
ble code is registered.
HYDRAULIC CIRCUITS AND VALVE OPERATION
The hydraulic shuttle valves control the flow of
pressurized brake fluid to the wheel brakes during
the different modes of ABS braking. The following
paragraphs explain how this works. For purposes of
explanation only, it is assumed that only the right
front wheel is experiencing antilock braking; the fol-
lowing diagrams show only the right front wheel in
an antilock braking operation.
NORMAL BRAKING HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 7) shows a vehicle
with traction control in the normal braking mode.
The diagram shows no wheel spin or slip occurring
relative to the speed of the vehicle. The driver is
applying the brake pedal; this builds pressure in the
brake hydraulic system to engage the brakes and
stop the vehicle. The hydraulic shuttle valve closes
with every brake pedal application so pressure is not
created at the inlet to the pump/motor.
Fig. 7 ABS With Traction Control - Normal Braking Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (OFF)
4 ± SUCTION VALVE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (OFF)
7 ± TO RIGHT FRONT WHEEL8 ± NORMALLY OPEN VALVE (OFF)
9 ± NORMALLY OPEN ASR VALVE (OFF)
10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± MASTER CYLINDER PRESSURE
13 ± NOISE DAMPER CHAMBER
PLBRAKES 5 - 71
DESCRIPTION AND OPERATION (Continued)

ABS BRAKING HYDRAULIC CIRCUIT, SOLENOID
VALVE, AND SHUTTLE VALVE FUNCTION (ABS
WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 8) shows the vehicle in
the ABS braking mode. The diagram shows one
wheel is slipping because the driver is attempting to
stop the vehicle at a faster rate than is allowed by
the surface on which the tires are riding.
²The hydraulic shuttle valve closes upon brake
application so that the pump/motor cannot siphon
brake fluid from the master cylinder.²The normally open and normally closed valves
modulate (build/decay) the brake hydraulic pressure
as required.
²The pump/motor is switched on so that the
brake fluid from the low pressure accumulators is
returned to the master cylinder circuits.
²The brake fluid is routed to either the master
cylinder or the wheel brake depending on the posi-
tion of the normally open valve.
Fig. 8 ABS With Traction Control - ABS Braking Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (ON)
4 ± SUCTION VALVE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (MODULATING)
7 ± TO RIGHT FRONT WHEEL
8 ± NORMALLY OPEN VALVE (MODULATING)9 ± NORMALLY OPEN ASR VALVE (OFF)
10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± MASTER CYLINDER PRESSURE
13 ± CONTROLLED WHEEL PRESSURE
14 ± LOW PRESSURE ACCUMULATOR PRESSURE
15 ± PUMP INTERSTAGE PRESSURE
16 ± NOISE DAMPER CHAMBER
5 - 72 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

ABS TRACTION CONTROL HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 9) shows the vehicle in
the traction control (TC) mode. The diagram shows a
drive wheel is spinning and brake pressure is
required to reduce its speed.
²The normally open TC (ASR) valve is energized
to isolate the brake fluid being pumped from the
master cylinder and to isolate the driven wheel.
²The normally open TC (ASR) valve bypasses the
pump output back to the master cylinder at a fixed
pressure setting.
²The normally open and normally closed valves
modulate (build/decay) the brake pressure as
required to the spinning wheel.
Fig. 9 Traction Control Hydraulic Circuit
1 ± OUTLET VALVE
2 ± PUMP PISTON
3 ± PUMP MOTOR (ON)
4 ± LOW PRESSURE ACCUMULATOR PRESSURE
5 ± LOW PRESSURE ACCUMULATOR
6 ± NORMALLY CLOSED VALVE (MODULATING)
7 ± TO RIGHT FRONT WHEEL (SPINNING)
8 ± NORMALLY OPEN VALVE (MODULATING)
9 ± NORMALLY OPEN ASR VALVE ON (REGULATING)10 ± FROM MASTER CYLINDER
11 ± HYDRAULIC SHUTTLE VALVE
12 ± CONTROLLED WHEEL PRESSURE
13 ± SUCTION VALVE
14 ± PUMP INTERSTAGE PRESSURE
15 ± NOISE DAMPER CHAMBER
16 ± MASTER CYLINDER PRESSURE
17 ± PUMP PRESSURE
PLBRAKES 5 - 73
DESCRIPTION AND OPERATION (Continued)

SERVICE PROCEDURES
BRAKE FLUID LEVEL CHECKING
CAUTION: Use only Mopar brake 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.
Refer to SERVICE PROCEDURES in the BASE
BRAKE SYSTEM section in this group for the proper
procedure to check and adjust the brake fluid level in
the master cylinder fluid reservoir.
ANTILOCK BRAKE SYSTEM BLEEDING
The base brake's hydraulic system must be bled
anytime air enters the hydraulic system. The ABS
though, particularly the ICU (HCU), should only be
bled when the HCU is replaced or removed from the
vehicle. The ABS must always be bled anytime it is
suspected that the HCU has ingested air. Under
most circumstances that require the bleeding of the
brakes hydraulic system, only the base brake
hydraulic system needs to be bled.
It is important to note that excessive air in the
brake system will cause a soft or spongy feeling
brake pedal.
During the brake bleeding procedure, be sure the
brake fluid level remains close to the FULL level in
the master cylinder fluid reservoir. Check the fluid
level periodically during the bleeding procedure and
add DOT 3 brake fluid as required.
The ABS must be bled as two independent braking
systems. The non-ABS portion of the brake system
with ABS is to be bled the same as any non-ABS sys-
tem.
The ABS portion of the brake system must be bled
separately. Use the following procedure to properly
bleed the brake hydraulic system including the ABS.
BLEEDING
When bleeding the ABS system, the following
bleeding sequence must be followed to insure com-
plete and adequate bleeding.
(1) Make sure all hydraulic fluid lines are installed
and properly torqued.
(2) Connect the DRB scan tool to the diagnostics
connector. The diagnostic connector is located under
the lower steering column cover to the left of the
steering column.
(3) Using the DRB, check to make sure the CAB
does not have any fault codes stored. If it does, clear
them using the DRB.WARNING: WHEN BLEEDING THE BRAKE SYSTEM
WEAR SAFETY GLASSES. A CLEAR BLEED TUBE
MUST BE ATTACHED TO THE BLEEDER SCREWS
AND SUBMERGED IN A CLEAR CONTAINER FILLED
PART WAY WITH CLEAN BRAKE FLUID. DIRECT
THE FLOW OF BRAKE FLUID AWAY FROM YOUR-
SELF AND THE PAINTED SURFACES OF THE VEHI-
CLE. BRAKE FLUID AT HIGH PRESSURE MAY
COME OUT OF THE BLEEDER SCREWS WHEN
OPENED.
(4) Bleed the base brake system using the stan-
dard pressure or manual bleeding procedure as out-
lined in SERVICE PROCEDURES in the BASE
BRAKE SYSTEM section at the beginning of this
group.
(5) Using the DRB, select ANTILOCK BRAKES,
followed by MISCELLANEOUS, then BLEED
BRAKES. Follow the instructions displayed. When
the scan tool displays TEST COMPLETED, discon-
nect the scan tool and proceed.
(6) Bleed the base brake system a second time.
Check brake fluid level in the reservoir periodically
to prevent emptying, causing air to enter the hydrau-
lic system.
(7) Fill the master cylinder reservoir to the full
level.
(8) Test drive the vehicle to be sure the brakes are
operating correctly and that the brake pedal does not
feel spongy.
MASTER CYLINDER BLEEDING
(1) Clamp the master cylinder in a vise.
(2) Attach Master Cylinder Bleed Tube, Special
Tool 8358-1, to the primary port of the master cylin-
der and tighten in place (Fig. 11). Attach Master Cyl-
inder Bleed Tube, Special Tool 8358-2, to the
secondary port of the master cylinder and tighten in
place. Position the other end of the tubes into the
master cylinder reservoir so their outlets are below
the surface of the brake fluid in the reservoir when
filled.
(3) Fill the brake fluid reservoir with Mopart
brake fluid, or an equivalent conforming to DOT 3
specifications.
(4) Using a wooden dowel as a pushrod (Fig. 11),
press the pistons inward slowly applying brake pres-
sure, then release the pressure, allowing the pistons
to return to the released position. Repeat this several
times until all air bubbles are expelled out of the
tubes and master cylinder bore.
(5) Remove the bleed tubes from the master cylin-
der and plug the outlet ports.
(6) Install the fill cap on the reservoir.
(7) Remove the master cylinder from the vise.
PLBRAKES 5 - 77

CLUTCH
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
MODULAR CLUTCH ASSEMBLY..............1
CLUTCH CABLE..........................1
CLUTCH INTERLOCK/UPSTOP SWITCH........1
DIAGNOSIS AND TESTING
CLUTCH SYSTEM DIAGNOSIS...............2
DRIVE PLATE MISALIGNMENT..............5
CLUTCH CHATTER COMPLAINTS............5
CLASH±INTO±REVERSE COMPLAINTS........5
CLUTCH INTERLOCK/UPSTOP SWITCH........5REMOVAL AND INSTALLATION
CLUTCH CABLE..........................7
CLUTCH INTERLOCK/UPSTOP SWITCH........8
MODULAR CLUTCH ASSEMBLY..............8
RELEASE BEARING AND FORK.............12
CLEANING AND INSPECTION
CLUTCH CONTAMINATION.................12
CLEANING PRECAUTIONS.................13
SPECIFICATIONS
TORQUE...............................13
DESCRIPTION AND OPERATION
MODULAR CLUTCH ASSEMBLY
All 2.0L SOHC engines equipped with the A578
5-speed transaxle use a modular clutch assembly
(Fig. 1). The transaxle must be removed to gain
access to and replace the modular clutch, drive plate,
and/or clutch release bearing and lever.
The modular clutch assembly used in this vehicle
consists of a single, dry-type clutch disc, a diaphragm
style clutch cover, and an integrated flywheel. The
clutch cover is riveted to the flywheel, containing theclutch disc within. The modular clutch can only be
serviced as an assembly.
The clutch disc has cushion springs riveted to the
disc hub assembly. The clutch disc facings are riveted
to the cushion springs. The facings are made from a
non-asbestos material.
The clutch cover pressure plate assembly is a dia-
phragm type unit with a one-piece diaphragm spring
with multiple release fingers. The pressure plate
release fingers are preset during manufacture and
are not adjustable.
CLUTCH CABLE
The clutch cable assembly (Fig. 2) carries the
movement of the clutch pedal to the clutch release
bearing. The cable is designed to maintain tension
against the clutch fork, or lever, and has a built in
self-adjusting mechanism, which compensates for
clutch disc wear.
CLUTCH INTERLOCK/UPSTOP SWITCH
DESCRIPTION
The clutch interlock/upstop switch is an assembly
consisting of two switches: an engine starter inhibit
switch (interlock) and a clutch pedal upstop switch
(Fig. 3). The switch assembly is located in the clutch/
brake pedal bracket assembly (Fig. 4), each switch
being fastened by four plastic wing tabs.
OPERATION
Clutch Interlock Switch
The clutch interlock switch prevents engine starter
operation and inadvertent vehicle movement with the
clutch engaged and the transaxle in gear.
Fig. 1 Modular Clutch Assembly
1 ± MODULAR CLUTCH ASSEMBLY
PLCLUTCH 6 - 1

CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH DISC
FACINGS HAVE
FRACTURED INTO
SMALL PIECESDriver performs a 5-1 downshift at vehicle
speed in excess of 60 miles per hourAlert driver to problem cause. Replace
modular clutch assembly.
Leak at rear main or transaxle input shaft
sealReplace modular clutch assembly. Replace
seal.
Excessive heat from slippage Replace modular clutch assembly
SERVICE DIAGNOSISÐIMPROPER CLUTCH RELEASE
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH DISC
BINDS ON INPUT
SHAFT SPLINESClutch disc hub splines damaged during
installationClean, smooth, and lubricate disc and shaft
splines. Replace modular clutch assembly
and/or input shaft if splines are severely
damaged.
Input shaft splines rough, damaged. Clean input shaft splines. Then lube.
Corrosion or rust formations on splines of
input shaft and discClean input shaft splines and disc splines,
then lube
CLUTCH DISC
RUSTED TO
FLYWHEEL
AND/OR
PRESSURE PLATEOccurs in vehicles stored or not driven for
extended period of time. Also occurs after
steam cleaning if vehicle is not used for
extended period.Replace modular clutch assembly
CLUTCH WILL NOT
DISENGAGE
PROPERLYDisc bent, distorted during transaxle
installationReplace modular clutch assembly
Clutch cover diaphragm spring damaged
during transaxle installationReplace modular clutch assembly
Release fork bent, loose, or damaged Replace fork if worn or damaged
Clutch cable binding or routed incorrectly Check and correct cable routing
Self-adjuster in cable not functioning
properly, resulting in excess cable slackPull on cable conduit at transaxle (as if
disconnecting cable) to check adjuster
operation
SERVICE DIAGNOSIS±CLUTCH PEDAL NOISE
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH PEDAL
MAKES REPEATED
ªPOPº NOISE IN
THE FIRST INCH
OF TRAVELSelf-adjusting mechanism in cable defective Replace clutch cable
CLUTCH PEDAL
SQUEAKS WHEN
DEPRESSED TO
FLOORPedal bushings worn out or inadequate
lubricationReplace or lubricate bushings
Clutch pedal return spring worn out Lubricate or replace return spring
Clutch release lever pivot stud has
inadequate lubricationLubricate or replace clutch release lever
6 - 4 CLUTCHPL
DIAGNOSIS AND TESTING (Continued)

SERVICE DIAGNOSIS±CLUTCH INTERLOCK/UPSTOP SWITCH
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE STARTER
WON'T CRANK
WHEN CLUTCH
PEDAL IS
PRESSED TO THE
FLOORClutch interlock switch does not have
continuity when plunger is depressed 1.25
mm (1.30 in.)Defective switch or open wiring circuit.
Replace switch if necessary.
Interlock switch plunger is not depressed
when clutch pedal is pushed to the floorFloor mat interferes with clutch pedal
movement or clutch pedal bracket is bent.
Problem is related to other components in
the starting circuit.Check other components in the starting
circuit. Refer to Battery/Starting/Charging
System in Group 8.
SPEED CONTROL
DOES NOT
TERMINATE WHEN
CLUTCH PEDAL IS
DEPRESSED BY AT
LEAST 33 mm (1.30
in.)Upstop switch circuit is closed when clutch
pedal is depressed, or harness is shorted.Refer to Upstop Switch Electrical Test in
this group. Repair wiring or replace switch
assembly as necessary.
Other speed control system failure. Refer to Group 8H, Speed Control for
further diagnosis and testing procedures.
REMOVAL AND INSTALLATION
CLUTCH CABLE
REMOVAL
(1) Disconnect both battery cables.
(2) Remove battery clamp and remove battery
from vehicle.
(3) Remove battery tray from mount bracket.
(4) Remove bellhousing cap (Fig. 7).
(5) Disconnect clutch cable from transaxle housing
and clutch release lever as shown in (Fig. 7).
(6) Disconnect the clutch cable from the clutch
pedal spacer (Fig. 8).
NOTE: Use care when handling clutch cable
assembly. Improper handling can cause adjuster
mechanism to come apart, making re-installation
difficult.
(7) Carefully guide cable through pedal assembly
bore and remove from vehicle.
INSTALLATION
(1) Insert the clutch pedal end of the cable into
position and connect the cable to the clutch pedal
spacer as shown in (Fig. 8).
(2) Verify adjuster mechanism function as follows:
(a) With slight pressure, pull the clutch release
lever end of the cable to draw the cable taut.(b) Push the clutch cable housing toward the
dash panel (With less than 25 lbs. of effort, the
cable housing should move 30-50mm.). If the cable
Fig. 7 Clutch Cable at Transaxle
1 ± CLUTCH CABLE
2 ± TRANSAXLE
3 ± BELLHOUSING CAP
PLCLUTCH 6 - 7
DIAGNOSIS AND TESTING (Continued)

RELEASE BEARING AND FORK
Remove the transaxle from the vehicle. See Group
21, Transaxle for removal and installation proce-
dures.
REMOVAL
(1) Move the lever and bearing assembly to a ver-
tical in-line position. Grasp the release lever with
two hands in the pivot stud socket area. Pull with
even pressure and the lever will pop off the pivot±
stud. Do not use a screwdriver or pry bar to pop off
the lever. This may damage the spring clip on the
lever.
(2) As a unit, remove the fork from the bearing
thrust plate. Be careful not to damage retention tabs
on bearing.
(3) Examine the condition of the bearing.It is
pre-lubricated and sealed and should not be
immersed in oil or solvent.
(4) The bearing should turn smoothly when held in
the hand under a light thrust load. A light drag
caused by the lubricant fill is normal. If the bearing
is noisy, rough, or dry, replace the complete bearing
assembly with a new bearing.
(5) Check the condition of the pivot stud spring
clips on back side of clutch fork. If the clips are bro-
ken or distorted, replace the clutch fork.
INSTALLATION
(1) The pivot ball pocket in the fork, as well as the
fork arms should be lubricated with grease prior to
installation.
(2) Assemble the fork to the bearing. The small
pegs on the bearing must go over the fork arms.
(3) Slide the bearing and fork assembly onto the
input shaft bearing retainer, as a unit.
(4) Snap the clutch fork onto the pivot ball.
(5) Reinstall transaxle assembly. Refer to Group
21, Transaxle for further information.
CLEANING AND INSPECTION
CLUTCH CONTAMINATION
Fluid contamination is a frequent cause of clutch
malfunctions. Oil, grease, water, or other fluids on
the clutch contact surfaces will cause faulty opera-
tion.
During inspection, note if any components are con-
taminated. Look for evidence of oil, grease, or water/
road splash on clutch components.
OIL CONTAMINATION
Oil contamination indicates a leak at the rear main
seal and/or transaxle input shaft. Oil leaks produce a
residue of oil on the transaxle housing interior, clutch
Fig. 18 Transaxle Removal/Installation
1 ± MODULAR CLUTCH ASSEMBLY
2 ± CLIP3 ± TRANSAXLE
4 ± CLUTCH MODULE BOLT (4)
VIEW A
6 - 12 CLUTCHPL
REMOVAL AND INSTALLATION (Continued)