wheel ISUZU TROOPER 1995 Workshop Manual

HYDRAULIC BRAKES 5A-21
MAIN DATA AND SPECIFICATIONS
GENERAL SPECIFICATIONS
Brake pedal
Pedal
free play
Pedal
height
Parking brake
Type Brake
handle(stem) travel
Master cylinder
Type
Piston bore diameter
TORQUE SPECIFICATIONS
mm (in)
mm (in)
mm (in)
13 (1131b·in)
Fig. 5A-23 6
to 10 (0.23 to 0.39)
208 to 218
(8.19 to 8.58)
Duo-servo
6 to 7 notches
When
pulled with a force of 30 kg (66 lb)
Dual-circuit
25.4 (1.000)
4-Wheel Antilock Brake System
N·m {lb·ft}
-Brake fluid pipe line -Flexible hose
Rear Wheel Antilock Brake System
-Brake fluid pipe line -Flexible hose

BRAKE PADS REPLACEMENT
1 Outer side
2
DISC BRAKES 5A2-3
Removal steps
1. Wheel and tire assembly
2. Lock
bolt 3. Caliper assembly
4. Pad assembly with shim
5. Clip
Installation
steps To install, follow the removal
steps in the reverse order.
*;Repair kit
Fig. 5A2-3
1••1 REMOVAL
NOTE:
If a squealing noise occurs from the front brake while
driving, check the pad wear indicator plate. If the
........., indicator plate contacts the rotor, the disc pad
assembly should be replaced.
•
Draw out two-thirds of the brake fluid from the
reservoir.
• Raise the vehicle and support it with suitable
safety stands.
1. Wheel and tire assembly
•
Refer to "Wheels and Tires" in Section 3E.
2. Lock bolt (Fig. 5A2-4)
3. Caliper assembly
• Support
the caliper assembly so that the brake
hose
is not stretched or damaged.
4. Pad assembly with shim
5. Clip
Fig. 5A2-4
1••1 INSTALLATION
5. Clip (Fig. 5A2-5)
Fig. 5A2-5

5A2-4 DISC BRAKES
4. Pad assembly with shim (Fig. 5A2-6, 7)
1-c::~t:.l• Apply ~pecial grease (approx 0.2 g) to both
contactmg surfaces
of inner shims. Wipe off
extruded grease after installing.
Inner shim
Wear
indicator Inner side
Fig. 5A2-6
Fig. 5A2-7
3. Caliper assembly (Fig. 5A2-8)
• Use adjustable pliers to bottom the piston into
the
caliper bore. Be careful not to damage the
piston
dust boot.
• Do not damage the flexible hose by twisting or
pulling it.
Fig. 5A2-8
2. Lock bolt (Fig. 5A2-9)
1«1 Torque N·m (lb·ft) 74 (54)
Fig. 5A2-9
1. Wheel and tire assembly
• Refer to "Wheels and Tires" in Section 3E.
• Pump the brake pedal several times to make
sure that the pedal is firm. Check the brake fluid
level in the reservoir after pumping the brakes.
SERVICING THE ROTOR
In the manufacturing of the brake rotor, all the
tolerances regarding surface finish,
parallelism and
lateral
runout are held very closely. The maintenance
of these tolerances provide the surface necessary to
assure smooth brake operation.
LATERAL RUNOUT
Lateral runout is the movement of the rotor from side
to side as it rotates on the spindle. This could also be
referred
to as "rotor wobble".
This movement causes the piston to be knocked back
into its bore. This results in
additional pedal travel and
a vibration during braking.

CHECKING LATERAL RUNOUT (Fig. 5A2-10)
1. Adjust the wheel bearing correctly.
•
Refer to "Front Drive Axle" in Section 4C.
2. Attach a dial indicator to some portion of the
suspension so that the stem contacts the
rotor
face about 29 mm (1.14 in) from the rotor edge.
3. Move the rotor one complete rotation.
• The lateral runout should not exceed 0.13 mm
(0.005 in)
~~~ Maximum runout mm (in) I 0.13 (0.005)
Fig. 5A2-1 0
'-' PARALLELISM (Fig. 5A2-11)
Parallelism is the measurement of the thickness of the
rotor at
four or more points around the circumference
of the rotor. All measurement must be made at 29 mm
(1.14 in) from the edge of the rotor.
The
rotor thickness must not vary more than 0.010 mm
(0.0004 in) from point to point.
~~~ Maximum parallelism mm (in) I 0.010 (0.0004)
----------1 '-----...
Fig. 5A2-11
'-' REPLACING BRAKE ROTORS
When installing new brake rotors, do not refinish the
surfaces. These parts are
atthe correct level of surface
finish.
DISC BRAKES 5A2-5
REFINISHING BRAKE ROTORS (Fig. 5A2-12)
Accurate control of the rotor tolerances is necessary
for proper performance ofthe disc brakes. Machining
of the rotor should be done only with precision
equipment.
All brake rotors have a minimum thickness
dimension cast into them. This dimension
is the
minimum wear dimension and not a refinish
dimension. The
minimum wear dimension is
24.60 mm (0.969 in). The minimum refinish dimension
is 24.97
mm (0.983 in).
When refinishing rotors,
always use sharp cutting tools
or bits. Dull or worn tools leave a poor surface finish
which
will affect initial braking performance. Vibration
dampening attachments
should always be used when
refinishing braking surfaces. These attachments
eliminate tool chatter and will result in better surface
finish.
After refinishing, replace any rotor that does not meet
the minimum thickness of 24.97 mm (0.983 in). Do not
use a brake rotor that will not meet the specification.
~~~ Minimum wear
dimension mm (in) 24.60 (0.969)
Refinish dimension
mm (in) 24.97
(0.983)
I
II lllJl I
1 t
I
Fig. 5A2-12

5A2-1 0 DISC BRAKES
REAR DISC BRAKE
BRAKE PADS INSPECTION (Fig. 5A2-28)
Check the outer pad by looking at each caliper from
above. Check the thickness on the inner pad by looking
down through the inspection hole in the top of the
caliper. Whenever the pad is worn to about the
thickness
of the pad base, the pad should be removed
for further measurements. The pad should be
replaced anytime the pad thickness (t) is worn to within
1.0 mm (0.039 in) of the pad itself. 'f'-~1~
The disc pads have a wear indicator that makes a noise
when the pad wear to a degree where replacement is
required.
~~~-M--in-im __ u_m_l-im--it _____ m_m--(i-n)-rl--,-.-0-(0-.-03_9_) ___
BRAKE PADS REPLACEMENT
EJ REMOVAL
NOTE:
1
*5
3
Fig. 5A2-29
If a squealing noise occurs from the rear brake while
driving, check the pad wear indicator plate. If the
indicator
plate contacts the rotor, the disc pad
assembly should be replaced.
•
Draw out two-thirds of the brake fluid from the
reservoir.
• Raise the vehicle and support it with suitable
safety stands.
1. Wheel and tire assembly
•
Refer to "Wheels and Tires" in Section 3E.
2. Lock bolt (Fig. 5A2-30) Fig.
5A2-28
Removal steps
1. Wheel and tire assembly 2. Lock bolt 3. Caliper assembly
4. Pad assembly with shim 5. Clip
Installation
steps
To
install, follow the removal steps in the reverse order.
* ; Repair kit
Fig. 5A2-30
•

5A2-12 DISC BRAKES
1. Wheel and tire assembly
• Refer to "Wheels and Tires" in Section 3E.
• Pump the brake pedal several times to
make sure that the pedal
is firm. Check the
brake fluid level in the reservoir after
pumping the brakes.
SERVICING THE ROTOR
In the manufacturing of the brake rotor, all the
tolerances regarding surface finish, parallelism and
lateral runout are held very closely. The maintenance
of these tolerances provide the surface necessary to
assure smooth brake operation.
LATERAL RUNOUT
Lateral runout is the movement of the rotor from side
to side as it rotates on the spindle. This could also be
referred
to as "rotor wobble".
This movement causes the piston to be knocked back
into its bore. This
results in additional pedal travel and
a vibration during braking.
CHECKING LATERAL RUNOUT (Fig. 5A2-36)
1. Attach a dial indicator to some portion of the
suspension so
that the stem contacts the rotor
face about 22 mm (0.87 in) from the rotor edge.
2. Move the rotor one complete rotation.
• The lateral runout should not exceed 0.13 mm
(0.005 in)
~~~ Maximum runout mm (in) I 0.13 (0.005)
Fig. 5A2-36
PARALLELISM (Fig. 5A2-37)
Parallelism is the measurement of the thickness of the
rotor at
four or more points around the circumference
of the rotor. All measurements must be made at
22 mm (0.87 in) from the edge of the rotor.
The rotor thickness
must not vary more than 0.010 mm
(0.0004 in) from point to point.
Maximum parallelism variation mm (in) 0
·01 0 (0.000 4
)
REPLACING BRAKE ROTORS
When installing new brake rotors, do not refinish the
surfaces. These parts are at the correct
level of surface
finish.
Fig. 5A2-37

5A2-14 DISC BRAKES
CALIPER REPLACEMENT
6
3
Fig. 5A2-40
1••1 REMOVAL
• Raise the vehicle and support with suitable
safety stands.
1. Wheel and tire assembly
• Refer to "Wheels and Tires" in Section 3E.
2. Brake flexible hose (Fig. 5A2-41)
• Remove the bolt and gaskets, then disconnect
the flexible hose
from the caliper.
• After disconnecting the flexible hose, cap or
tape the openings to prevent entry of foreign
material.
• Since the brake fluid flows out from the
connecting
coupler, place a drain pan under
the
vehicle.
1
Removal steps
1. Wheel and tire assembly
2. Brake flexible hose
3. Lock bolt 4. Guide bolt 5. Caliper assembly 6. Support bracket
7.
Pad assembly with shim
8.
Clip
Installation
steps
To install, follow the removal steps in the reverse order.
*;Repair kit
Fig. 5A2-41

5A2-16 DISC BRAKES
2. Brake flexible hose (Fig. 5A2-47)
• Always use new gaskets.
• Be sure to put the hooked edge of the flexible
hose end into the anti-rotation cavity.
~~~ Torque N-m (lb·ft) 35 (26)
Hooked edge
Fig. 5A2-47
1. Wheel and tire assembly
• Refer to "Wheels and Tires" in Section 3E.
• Bleed brakes. Refer to "Hydraulic Brakes" in
Section 5A.
•

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
--'--
•