DRIVE-OFF CYCLE
The DRIVE-OFF CYCLE takes place when the ve-
hicle reaches about 3 miles per hour the first time af-
ter an ignition reset. During this test, the modulator
solenoid valves are activated briefly to test their
function. The DRIVE-OFF CYCLE will be bypassed
if you drive-off with the service brake pedal de-
pressed.
LATCHING VERSUS NON-LATCHING FAULTS
Some faults detected by the (CAB) are latching.
The fault is latched and (ABS) function is disabled
until the ignition switch is reset (turned OFF/ON).
Thus (ABS) function is disabled even if the original
fault has disappeared during the ignition cycle in
which it occurred. Other faults are non-latching; any
warning lights that are turned on are only on as long
as the fault condition exists. As soon as the condition
goes away. The Amber Anti-Lock Warning Light is
turned off. Although a fault code will be set in most
cases. (Example:low accumulator fault will not be
stored for a time of 2 minutes after the fault is de-
tected).
BENDIX ABS SYSTEMS DIAGNOSTICS
The Bendix Anti-Lock 10 Brake System diagnos-
tics. Beyond the basic mechanical diagnostics, sys-
tems and components covered earlier in this section,
is accomplished by using the DRB II diagnostic
tester. See testing procedures outlined in the Bendix
Anti-Lock 10 Diagnostics Manual for the 1993 M.Y.
Please reference the above mentioned manual. For
any further diagnostic service procedures that are re-
quired on the Bendix Anti-Lock 10 Brake System, re-
quiring the use of the DRB II diagnostic tester.
ON CAR HYDRAULIC ABS COMPONENT SERVICE
WARNING: FAILURE TO FULLY DE-PRESSURIZE
THE HYDRAULIC ACCUMULATOR BEFORE PER-
FORMING HYDRAULIC SYSTEM SERVICE OPERA-
TIONS. COULD RESULT IN INJURY TO SERVICE
PERSONNEL AND OR DAMAGE TO PAINTED SUR-
FACES. SEE SECTION 2 FOR ADDITIONAL WARN-
INGS AND CAUTIONS.
GENERAL SERVICE PRECAUTIONS
The following are general precautions that should
be observed when servicing the Anti-Lock Brake Sys-
tem and/or other vehicle systems. Failure to observe
these precautions may result in Anti-Lock brake sys-
tem damage.
If welding work is to be performed on the vehicle,
using an electric arc welder, the (CAB) connector
should be disconnected during the welding operation.
The (CAB) or hydraulic assembly connector should
never be connected or disconnected with the ignition
switch in the ON position.
Many components of the Anti-Lock brake system are
not serviceable and must be replaced as an assembly.
Do not attempt to disassemble any component
that is not designed to be a serviced component.
DE-PRESSURIZING HYDRAULIC ACCUMULA-
TOR
The pump/motor assembly will keep the hydraulic
accumulator charged to approximately 11,032 and
13,790 kPa (1600 and 2000 psi) any time that the
ignition is in the ON position. The pump/motor assem-
bly cannot run if the ignition is off or if either battery
cable is disconnected.
Unless otherwise specified, the hydraulic accumula-
tor should be de-pressurized before disassembling any
portion of the hydraulic system. The following proce-
dure should be used to relieve the pressure in the
hydraulic accumulator:
(1) With ignition off, or either battery cable discon-
nected, pump the brake pedal a minimum of 40 times,
using approximately 222 N (50 lbs.) pedal force. A
noticeable change in pedal feel will occur, when the
accumulator is discharged.
(2) When a definite increase in pedal effort is felt,
pump pedal a few additional times. This will insure
removal of all hydraulic pressure from the brake sys-
tem.
CHECKING BRAKE FLUID LEVEL
CAUTION: Use only brake fluid conforming to DOT 3
specifications such as Mopar
T
or Equivalent. Do not
use any fluid in the brake hydraulic system, which
contains a petroleum base. Do not use a container
which has been used for petroleum based fluids or a
container that is wet with water. Petroleum based
fluids will cause swelling and distortion of rubber
parts in the hydraulic brake system and water will mix
with brake fluid, lowering the fluid boiling point. Keep
all brake fluid containers tightly capped to prevent
contamination.
The hydraulic assembly is equipped with a plastic
fluid reservoir, with a filter/strainer located in the filler
neck of each reservoir section.
The Anti-Lock brake system requires that the hy-
draulic accumulator be de-pressurized when checking
the fluid level. To check the brake fluid level, the
following procedure should be used:
(1) With the ignition off, de-pressurize the hydraulic
accumulator by applying the brake pedal approxi-
mately 40 times, using a pedal force of approximately
220 N (50 lbs.). A noticeable change in pedal feel will
occur when the accumulator is de-
Ä
ANTI-LOCK 10 BRAKE SYSTEM
5 - 93