Chrysler neon 1997 Service Manual page 153

5 - 76 BRAKES
DIAGNOSIS AND TESTING (Continued)
a malfunction has occurred with one of the propor-
tioning valves.
One proportioning valve controls the right rear
brake, and the other proportioning valve controls the
left rear brake.
If a malfunctioning proportioning valve is sus-
pected on a vehicle equipped with the Bendix ABX-4
ABS Brake System, refer to Proportioning Valve Test
With ABS Brakes in the Base Brake Diagnosis And
Testing Section in this group of the service manual.
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts.
Swollen rubber parts indicate 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 fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brakes hydraulic unit and all hydraulic
fluid hoses.
VEHICLE TEST DRIVE INFORMATION AND
PROCEDURE
Most ABS complaints will require a test drive as a
part of the diagnostic procedure. The purpose of the
test drive is to duplicate the condition.
NOTE: Remember conditions that result in the
turning on of the Red BRAKE Warning Lamp may
indicate reduced braking ability. The following pro-
cedure should be used to test drive an ABS com-
plaint vehicle.
Before test driving a brake complaint vehicle, note
whether the Red Brake Warning Lamp or Amber
ABS Warning Lamp is turned on. If it is the Red
Brake Warning Lamp, refer to the hydraulic system
section in the brake group of this manual. If the ABS
Warning lamp was/is on, test drive the vehicle as
described below, to verify the complaint. While the
ABS Warning Lamp is on, the ABS system is not
functional. The standard brake system and the abil-
ity to stop the car is not be affected if only the ABS
Warning Lamp is on.
(1) Turn the key to the off position and then back
to the on position. Note whether the ABS Warning
Lamp continues to stay on. If it does, refer to the
ABX-4 Diagnostic Manual for the required test pro-
cedures.
(2) If the ABS Warning Lamp goes out, shift into
gear and drive the car to a speed of 5 mph to com-
plete the ABS start up cycle. If at this time the ABS
Warning Lamp goes on refer to the ABX-4 Diagnostic
Manual.
(3) If the ABS Warning Lamp remains OUT, drive
the vehicle a short distance. During this test drive be
sure that the vehicle achieves at least 25 mph. Brake
to at least one complete stop and again accelerate to
25 mph.
(4) If a functional problem with the ABS system is
determined while test driving a vehicle, refer to the
ABX-4 Diagnostics Manual for required test proce-
dures and proper use of the DRB tester.
ABS SERVICE PRECAUTIONS
The ABS uses an electronic control module, the
CAB. This module is designed to withstand normal
current draws associated with vehicle operation.
Care must be taken to avoid overloading the CAB
circuits. In testing for open or short circuits, do
not ground or apply voltage to any of the cir-
cuits unless instructed to do so for a diagnostic
procedure. These circuits should only be tested
using a high impedance multi-meter or the DRB
tester as described in this section. Power should
never be removed or applied to any control module
with the ignition in the ON position. Before removing
or connecting battery cables, fuses, or connectors,
always turn the ignition to the OFF position.
CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of after-market electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, ect.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.
SERVICE PROCEDURES
BRAKE FLUID LEVEL INSPECTION
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.
For the specific procedure covering the inspection
of the brake fluid level and adding brake fluid to the
reservoir, refer to the Service Adjustments Section in
this group of the service manual.
BLEEDING PROCEDURE INFORMATION
The base brake system must be bled anytime air is
permitted to enter the hydraulic system, due to dis-
connection of brake tubes, hoses or components. The
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