brake sensor ISUZU TROOPER 1995 User Guide

AXLE SHAFT
1
I
1••1 REMOVAL
Preparation:
• Raise the vehicle.
12 11
2
Fig. 4B-6
• Remove tires and wheels. Refer to Section 3E
"WHEELS & TIRES".
1. Brake caliper
• Use a wire to attach the brake caliper to the
frame. Refer to
Section 5A2 "DISC BRAKES".
2. Brake disc
3. ABS sensor (If equipped with ABS)
4. Parking brake assembly
• Refer to Section 5C "PARKING BRAKES".
5. Bolt (Behind the back plate)
• Remove the parking brake cable mounting
bolts (Fig. 4B-7).
REAR AXLE 48-7
Removal steps
1. Brake caliper
2. Brake disc
3. Antilock brake system (ABS)
speed sensor
4. Parking brake assembly
5. Bolt
6. Nut 7. Axle shaft assembly 8. Snap ring
9. Retainer
10. Bearing
11. Bearing holder
12. Back plate
13. Wheel pin
Installation steps To install, follow the removal
steps
in the reverse order.
Bolt
Fig. 4B-7

1 t!!.l Axle shaft flange run-out (Fig. 4B-12)
Limit mm (in) I 0.08 (0.003)
160 mm (6.3 in)
Fig. 4B-12
OIL SEAL REPLACEMENT
• Remove the oil seal carefully not to damage
the bearing holder bore (Fig. 4B-13).
When installing, use special tool.
1®1 Oil seal installer: J-39379
Fig. 4B-13
I••IINSTALLATION
13. Wheel pin
12. Back plate
11. Bearing holder
10. Bearing
9. Retainer
J-39379
1 ®I • Using a special tool, press fit together with
the bearing (Fig. 4B-14).
Bearing
installer: J-39212
8.
7.
6.
Fig. 4B-14
Snap ring
Axle shaft assembly
NOTE:
REAR AXLE 48-9
39212
Be sure not to damage the oil seal.
Nut
• Tighten the bearing holder mounting nut to
the specified torque.
I~I ___ T_o_rq_u_e __ N_·_m_(_lb_·f_t)~l _____ 7_4_(~5~4) ____ ___
5
4.
3.
2.
1
Bolt (Behind the back plate)
• Fix the parking brake cable mounting bolt.
Parking brake assembly
• Refer to Section 5C "PARKING BRAKES".
Antilock brake system sensor (If equipped with
antilock brake system)
Brake disc
Brake caliper
• Refer to Section 5A2 "DISC BRAKES".

E) INSTALLATION
5. Collapsible spacer
• Discard the used collapsible spacer and install
a new one.
4. Outer bearing
NOTE:
• Do not drive in, but just temporarily set in the
outer bearing
by hand, which should be
indirectly pressed in finally by tightening the
flange nut.
3. Oil seal
1"?.:\1 • Use the seal installer to install a new oil seal that
l.::::'i:il has been soaked in axle lubricant.
Installer:
J-37263
DIFFERENTIAL ASSEMBL V
~ 1
REAR AXLE 48-11
J-37263
Pinion oil seal
Fig. 4B-17
2. Flange
1. Flange nut
• Refer to "DIFFERENTIAL ASSEMBLY (UNIT
REPAIR)" for flange nut reassembly in this
section.
NOTE:
• Discard the used nut and install a new one.
3
/
Removal steps
1. Parking brake cable
2. Nut 3. Axle shaft assembly 4. Bolt and nut 5. Differential assembly
Installation
steps
To install, follow the removal steps in the reverse order.
Fig. 4B-18
E) REMOVAL
Preparations:
• Jack up and .support the frame with stands.
• Remove the wheel and tire. Refer to Section 3E
"WHEELS & TIRES".
•
Drain the differential oil. •
Remove
the propeller shaft. Refer to Section 4A
"PROPELLER SHAFT".
•
Remove the RWAL speed sensor. Refer to Section
5A3
"REAR WHEEL ANTILOCK BRAKE SYSTEM
(RWAL)".
•
Remove the ABS speed sensor. Refer to Section
5A4
"4-WHEEL ANTI-LOCK BRAKE SYSTEM
(ABS)".

l•!•l DISASSEMBLY
•
•
•
Jack up the vehicle and support it using jack
stands.
Remove the
tire and wheel.
Remove the drain bolt to drain differential oil.
NOTE:
•
During the work, be sure that the diff case is
supported by the jack (Fig. 4C-7).
Fig.
4C-7
• Remov: the brake caliper fixing bolt and hang
the caliper. Refer to Section 5A2 "DISC
BRAKES".
•
Remove the antilock brake system speed
sensor.
(If equipped with antilock brake
system) Refer
to Section 5A4 "4-WHEEL ANTI­
LOCK
BRAKE SYSTEM (ABS)".
1. Hub assembly (Disc, back plate and knuckle)
• Remove the locking hub. Refer to this Section
"FRONT HUB AND DISC".
•
Disconnect the knuckle and the suspension
arm. Refer
to Section 3C "FRONT SUSPEN­
SION".
2. Steering link and arm assembly
• Refer to Section 3B3 "STEERING LINKAGE".
3. Suspension crossmember
4. Propeller shaft
• Refer to Section 4A "PROPELLER SHAFT".
5. Mounting bolt and nut (Fig. 4C-8)
FRONT DRIVING AXLE 4C-7
Fig. 4C-8
6. Washer and spacer
7. Bolt (Fig. 4C-9)
• Remove the mounting bracket fixing bolt.
Fig. 4C-9
8. Front axle case assembly and front drive shaft
assembly (LH side) (Fig. 4C-10)
• Lower the vehicle and disconnect the RH front
drive shaft assembly, and then remove the
front axle case assembly and front drive shaft
assembly (LH).
Fig. 4C-10

1•! .. 1 DISASSEMBLY
•
Shift the transfer lever to the "2H" position and
move the vehicle forward and rearward about
one meter.
• Remove the 14mm hex bolts.
• Before disassembly, jack up the front of vehicle
and
support frame with jack stands.
• Remove the disc brake caliper assembly and
hang
it on the frame with wires. Refer to Section
5A2
"DISC BRAKES".
1. Bolt (Fig. 4C-73)
Fig. 4C-73
2. Hub cap
3. Housing
4. Snap ring and shim
5. Drive clutch assembly
6. Inner cam assembly
7. Lock washer and lock screw
8. Hub nut (Fig. 4C-74)
1®.1 Wrench: J-36827
Fig. 4C-74
Front hub nut wrench (J-36827)
FRONT DRIVING AXLE 4C-29
9. Hub and disc assembly
10. ABS
sensor ring (if so equipped)
11.
Outer bearing outer race
12.
Oil seal
13. Inner bearing outer race
1) Remove the outer bearing from the hub with
fingers. The inner bearing will remain in the
hub and may be removed after prying out the
inner bearing lip seal assembly (Fig. 4C-75).
2) Remove the outer race by driving out the
race from the hub with a brass drift inserted
behind
the race in the notches in the hubs.
Inner bearing
outer race
Fig. 4C-75
14.
Bolt (Fig. 4C-76)
• If necessary, replace the wheel pin in the
following manner.
1) Apply a scribe mark to disc to hub.
2) Clamp the hub and disc assembly in a vise,
using protective pads. Remove
the 6 disc­
to-hub retaining bolts.
Scribe mark
Fig. 4C-76

4C -30 FRONT DRIVING AXLE
15. Wheel pin (Fig. 4C-77)
• Place
hub on a suitable work surface and
remove the
wheel studs, as required, using a
hammer.
Fig. 4C-77
I L•IINSPECTION AND REPAIR
Make necessary correction or parts replacement if
wear, damage, corrosion or any other abnormal
condition are found through inspection.
Check
the following parts.
• Hub
• Hub bearing oil seal
• Knuckle spindle
•
Disc
• Caliper
•
Automatic locking hubs
• ABS sensor ring
For inspection and servicing
of disc caliper and
related parts, refer to Section 5A2 "DISC BRAKES".
rfil Inside diameter of housing measurement (Fig.
~ 4C-78)
mm(in)
Standard Limit
65.04 (2.561)
65.24 (2.568)
Inspect flange surface A and 8 for excessive wear.
A ---....
1 I
'-/ I
i/ 8mm (Measuring point) I I
~.
e
Fig. 4C-78
rfil Drive clutch section
~ measurement (Fig. 4C-79)
Standard
8.2 (0.323)
L
Fig. 4C-79 dimensions
ulu
mm(in)
Limit
7.8
(0.307)
1@ 1 Hold ring sliding resistance check (Fig. 4C-80)
Check the sliding resistance along opening
direction as shown in the figure.
N (lb)
Sliding Resistance 16.7-34.3 (3.8-7.7)
......
Fig. 4C-80

HYDRAULIC BRAKES 5A-17
ON-VEHICLE SERVICE
FLUID RESERVOIR TANK
2
T 4
3 1
Removal steps
1. Electrical connector 2. Retainer
3. Fluid reservoir
4. 0-ring
Installation steps
To install, follow the removal steps in the reverse order.
Fig. 5A-16
1••1 REMOVAL
NOTE:
Before removing fluid reservoir, remove brake fluid
from fluid reservoir.
1. Electrical connector
2. Retainer (Fig. 5A-17)
Fig. 5A-17
3. Fluid reservoir
• The fluid level sensor is built into the fluid
reservoir (Except rear wheel anti lock model). It
cannot be removed for servicing.
4. 0-ring
1••1 INSTALLATION
To install, follow the removal steps in the reverse
order, noting the
following points;
4. 0-ring (Fig. 5A-18)
• 0-ring must be set onto the fluid reservoir,
before
installing fluid reservoir.
Fluid reservoir
0-ring
Fig. 5A-18

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-1
SECTION 5A3
REAR WHEEL ANTILOCK BRAKE SYSTEM
(RWAL}
w CAUTION:
• All brake attaching fasteners are an important attaching part in that they could affect performance of vital
parts and systems, and/or could result in major repair expense. They must be replaced with one of the same
part
number or with an equivalent part if replacement becomes necessary. Do not use replacement parts of
lesser quality or substitute design. Torque values must be used as specified during reassembly to assure
proper retention of these parts.
CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5A3· 1
General Description . .
. . . . . . . . . . . . . . .
5A3· 1
Rear
Wheel Antilock (RWAL) Control
Parts Location . .

. . . . . . . . . . . . . . . . .
5A3· 5
System Diagram . .

. . . . . . . . . . . . . . . . . . . .
5A3· 6
Rear
Wheel Antilock (RWAL) System
Diagnostics . .

. . . . . . . . . . . . . . . . . . . . . .
5A3· 7
On-Vehicle Service . .

. . . . . . . . . . . . . . . . .
5A3·38
RWAL Electronic Brake Control
Module (EBCM) Replacement ....... 5A3-38
Antilock
(Isolation/Dump) Valve
Replacement ..................... 5A3-39
Speed Sensor Replacement
.......... 5A3-40
Main Data and Specifications ........... 5A3-41
Torque Specifications
............... 5A3-41
INTRODUCTION
This section deals with the complete diagnosis and
services
for vehicles equipped with rear wheel
antilock.
For service information regarding all other
components
of the brake system, refer to "Hydraulic
Brakes"
(Sec. SA), "Brake Booster System" (Sec. SA 1)
or "Disc Brakes" (Sec. SA2) of this Manual.
GENERAL DESCRIPTION
The rear wheel anti lock system (RWAL) is designed to
reduce rear wheel lock-up during a severe brake
application,
thus maintaining rear end stability. The
system functions
by regulating the rear hydraulic
brake line pressure. The pressure regulation is
accomplished
by an anti lock valve which is located on
the
front right side of engine room. The anti lock valve
is made up of two valves, a dump valve which releases
pressure into an accumulator and an isolation valve
which maintains rear brake pressure. The valve is
controlled
by a microcomputer which is part of the
Electronic Brake Control Module (EBCM). The
EBCM is mounted at the
front of the center
console. Under severe brake application, as pressure
is
applied to the brake pedal, the EBCM is designed to
permit the valve to do one of three functions or a
combination
of all three. The EBCM will allow the valve
to either maintain the same amount of hydraulic
pressure, release hydraulic pressure through the
dump valve into the accumulator or increase the
pressure by
pulsing the isolation valve.
The EBCM operates by receiving signals from the
speed sensor (which
is located in the differential
carrier), combination
valve and the brake light switch.
The RWAL system is connected
to the RWAL indicator
light located on the dash. An indication of the RWAL
operation and a
bulb check is performed each time the
ignition is turned
"ON". The indicator light will remain
on
for about two seconds. A RWAL system
malfunction is indicated if the RWAL indicator light
stays on, or comes on during driving. To determine the
specific
trouble, refer to "RWAL System Diagnostics"
in this section.

5A3-2 REAR WHEEL ANTILOCK BRAKE SYSTEM
To front brakes Combination valve
Anti lock valve
Accumulator
•
- -

- -
Electric
.,_ __ Hydraulic
I I I I I ~-------------------1 1--------------------
1_---------------------
Speed sensor
~----1 I
Fig. 5A3-1
12V DC I I
I
I
I
GRND
---, I I I
I
I
--'--
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-3
ELECTRONIC BRAKE CONTROL MODULE
(EBCM)
The electronic brake control module is microprocessor
based and is located on the
front end of the center
Power source
console. It performs three different algorithms to
calculate excessive wheel deceleration and performs
self check diagnostics.
Ground
~
Wheel speed sensor TACHOMETER
ALGORITHM
Valve reset
Brake
switch
PERFORMANCE
ALGORITHM o-+ ...
Isolation solenoid
Dump solenoid
SELF CHECK AND FAILSAFE
ALGORITHM
Differential switch, br<'!ke warning light
~
Fig. 5A3-2
ANTILOCK (ISOLATION/DUMP) VALVE
The antilock (dual solenoid hydraulic) valve is located
between the rear brakes and the combination valve
and is attached on the
front right side of engine room.
The valve contains
an isolation valve, dump valve and
an accumulator and is electrically connected to the
electronic control module.
The normal positions
for the antilock valve com­
ponents are
as follows;
1. Isolation valve is normally open (flow through
under normal braking).
2. Dump valve is normally closed.
3. Accumulator is empty.
Once the rear wheel antilock is activated, the EBCM
closes the isolation valve. If closing of the isolation
valve is insufficient to prevent wheel lock, the
EBCM
will open the dump valve to allow some rear brake fluid
into the accumulator, thus reducing brake pressure.
The
EBCM will continue to monitor wheel deceleration,
and
if it is still excessive will cause the antilock valve to
dump fluid to the accumulator again. This process will
be repeated until the appropriate wheel speed
correction is calculated by the
EBCM.
When the brake pedal is released, the isolation valve
de-energizes and any fluid in the accumulator is
returned to the master cylinder.
Normal brake operation is resumed.
Fig. 5A3-3