brakes ISUZU TROOPER 1995 Owner's Manual

HYDRAULIC BRAKES 5A-5
ON-VEHICLE SERVICE
FILLING MASTER CYLINDER
RESERVOIR
'\fl CAUTION:
'VI • Use only specified brake fluid. Do not use any
fluid which contains a petroleum base. Do not
use a container which has been used for
petroleum based fluids or a container which is
wet with water. Petroleum based fluids will
cause swelling and distortion of rubber parts in
the
hydraulic brake system. Water mixed with
brake fluid lowers the fluid boiling point. Keep
all fluid containers capped to prevent contami­
nation.
• Always fill the master cylinder reservoir when
the engine is
cold.
•
Never allow the brake fluid to come in contact
with the painted surfaces.
The master
cylinder reservoir must be kept properly
filled
to ensure adequate reserve and to prevent air
and moisture
from entering the hydraulic system.
However, because
of expansion due to heat absorbed
from the brakes and the engine, the reservoir must not
be overfilled. The brake fluid reservoir is on the master
cylinder, which is located under the hood on the
left
side of the cowl. Thoroughly clean reservoir cap
before
removal to avoid getting dirt into reservoir.
Remove cap and diaphragm.
Add fluid as required to
bring level to the "MAX" mark on the reservoir tank.
Use
"DOT 3" Hydraulic Brake Fluid. If the fluid cap
diaphragm is stretched, return
it to the original position
before
installing.
DETERIORATION OF BRAKE FLUID
Using any other brake fluid than specified or brake fluid
with mineral oil or water mixed in will drop the boiling
point of brake fluid. It may, in turn, result in vapor lock
or deteriorated rubber parts of the hydraulic system.
Be sure to change brake fluid at specified intervals.
If rubber parts are deteriorated, remove all the system
parts and
clean them with alcohol. Prior to reassembly,
dry the cleaned parts with air to remove the alcohol.
Replace all
hoses and rubber parts of the system.
LEAKAGE OF BRAKE FLUID
With engine idling, set shift lever in the neutral position
and continue to depress brake
pedal at a constant
pressure.
Should the pedal stroke become deeper gradually,
leak from the hydraulic pressure system is possible.
Make sure
by visual check that there is no leak.
BLEEDING BRAKE HYDRAULIC SYSTEM
A bleeding operation is necessary to remove air from
the hydraulic brake system whenever air is introduced
into the hydraulic system.
It may be necessary to bleed
the hydraulic system at all four brakes if air has been
introduced through a
low fluid level or by dis­
connecting brake pipes at the master cylinder. If a
brake pipe is disconnected at one
wheel, only that
wheel cylinder/caliper needs to be bled. If pipes are
disconnected at any fitting
located between master
cylinder and brakes, then the brake system served by
the disconnected pipe must
be bled.
1. For 4-wheel Antilock Brake System (ABS)
equipped
vehicle, be sure to remove the ABS
main fuse
40A located at the relay and fuse box
before
bleeding air. If you attempt to bleed air
without removing the main fuse, air cannot be let
out thoroughly, and this may cause damage to the
hydraulic unit.
After bleeding air, be sure to
replace the ABS main fuse back to its original
position.
2. Set the parking brake completely, then start the
engine.
NOTE:
The vacuum booster will be damaged if the
bleeding operation is performed with the engine
off.
3. Remove the master cylinder reservoir cap.
4. Fill the master cylinder reservoir with brake fluid.
Keep the reservoir at least half full during the air
bleeding operation.
5. Always use new brake fluid for replenishment.
6. In replenishing brake fluid, take care that air
bubbles do not enter the brake fluid.
•
When the master cylinder is replaced or
overhauled, first bleed the air from the master
cylinder, then from each
wheel cylinder and
caliper following the procedures described
below.
Bleeding the master cylinder (Fig. 5A-1}
7. Disconnect the rear wheel brake pipe master
cylinder (Fig. 5A-1 ). Check the fluid level
and replenish as necessary. If replenished, leave
the system for at least one minute.
8. Depress the brake pedal slowly once and hold it
depressed.
9. Completely seal the delivery port of the master
cylinder where the pipe was disconnected with
your finger, then release the brake pedal slowly.
10. Release your finger from the delivery port when
the brake
pedal returns completely.
11. Repeat steps 7 through 9 until the brake fluid
comes out of the delivery port during step 7.

5A-6 HYDRAULIC BRAKES
NOTE:
Do not allow the fluid level in the reservoir to go below
the half-way mark.
12. Reconnect the brake pipe
(j) to the master
cylinder and tighten the pipe.
13. Depress the brake pedal
slowly once and hold it
depressed.
14. Loosen the rear wheel brake pipe (j) at the master
cylinder (Fig. 5A-1).
15. Retighten the brake pipe, then release the brake
pedal
slowly.
16. Repeat steps 13 through 15 until no air comes out
from the port when the brake pipe is loosened.
NOTE:
Be very careful not to allow the brake fluid to come in
contact
with painted surfaces.
17. Bleed the air from the front wheel brake pipe
connection
® by repeating steps 7 through 16
(Fig.
5A-1 ).
Fig. 5A-1
Bleeding the caliper
18. Bleed the air from each wheel in the order listed
below.
• Right rear caliper
• Left rear caliper
• Right front caliper
• Left front caliper
If brake fluid does not come out or brake fluid does
not remain in the master cylinder while bleeding
each
caliper in the order listed above, the master
cylinder may contain air in its bore. First bleed the
master cylinder
as described in step 7 through 17.
19.
Place the proper size box end wrench over the
bleeder screw.
20. Cover the bleeder screw with a transparent tube,
and submerge the free end
of the transparent
tube in a transparent container containing brake
fluid.
21. Pump the brake pedal slowly three (3) times
(once/sec), then
hold it depressed.
22. Loose the bleeder screw until fluid flows through
the tube.
23. Retighten the bleeder screw.
24. Release the brake pedal slowly.
25. Repeat step 21 through 24 until the air is com­
pletely removed.
It may be necessary to repeat
the bleeding procedure
10 or more times for front
wheels and 15 or more times for rear wheels.
26. Go to the next wheel in the sequence after each
wheel is bled.
Be sure to monitor reservoir fluid
level.
27. Depress the brake pedal to check if you feel
"sponginess" after the air has been removed from
all wheel cylinders and calipers. If the pedal feels
"spongy", the entire bleeding procedure must be
repeated.
28. After the bleeding operation is completed on each
individual wheel, check the level
of brake fluid in
the reservoir and replenish up to the
"MAX" level
if necessary.
29. Attach the reservoir cap.
• If the diaphragm inside the cap is deformed,
reform
it and install.
30. Stop the engine.
FLUSHING BRAKE HYDRAULIC SYSTEM
It is recommended that the entire hydraulic system be
thoroughly flushed with clean brake fluid whenever
new parts are
installed in the hydraulic system.
Approximately one quart
of fluid is required to flush the
hydraulic system.
The system
must be flushed if there is any doubt as to
the grade
of fluid in the system or iffluid has been used
which contains the
slightest trace of mineral oil. All
rubber parts that have been subjected to a con­
taminated fluid
must be replaced.
BRAKE PIPES AND HOSES
The hydraulic brake system components are inter­
connected
by special steel piping and flexible hoses.
Flexible hoses are used between the frame and the
front calipers, the frame and rear axle case and the rear
axle and the rear calipers.
When the hydraulic pipes have been disconnected
for
any reason, the brake system must be bled after
reconnecting the pipe; refer to
"Bleeding the Brake
Hydraulic
System" in this section.
BRAKE HOSE INSPECTION
The brake hoses should be inspected at least twice a
year. The brake hose assembly should
be checked for
road hazard, cracks and chafing ofthe outer cover, and
for leaks and blisters. Inspect for proper routing and
mounting
of the hose. A brake hose that rubs on
suspension components
will wear and eventually fail.
A light and mirror may be needed for an adequate
inspection.
If any of the above conditions are observed
on the brake hose, adjust
or replace the hose as
necessary.
\fl CAUTION:
'V Never allow brake components such as calipers
to hang from the brake hoses, as damage to the
hoses may occur.

BRAKE HOSE REPLACEMENT
HYDRAULIC BRAKES 5A-7
Front I rear caliper brake hose
Removal steps 1. Brake pipe
2. Clip 3. Bolt and gasket
4. Hose
Installation steps To install, follow the removal steps in the reverse order.
Rear axle brake hose Removal steps
1. Brake pipe
2. Clip 3. Brake pipe
4. Bolt
5. Hose
Installation steps To install, follow the removal steps in the reverse order.
Fig. 5A-2
l••l REMOVAL
Preparation:
• Raise the vehicle and support it with suitable
safety stands.
• Remove wheel and tire assembly.
• Clean dirt, grease, and other foreign material
off the hose fittings at both ends.
Front/Rear Caliper Brake Hose
1. Brake pipe
2. Clip
3. Bolt and gasket
4. Hose
Rear Axle Brake Hose
1. Brake pipe
2. Clip
3. Brake pipe
4. Bolt
5. Hose
1••1 INSTALLATION
To install, follow the removal steps in the reverse
order, noting the following points. After installing the
brake
hoses, bleed brakes as described in this section.
Front/Rear Caliper Brake Hose
1. Tighten the brake pipes to the specified torque.
1«1 Torque N-m (lb·ft) 16 (12)
2. Tighten the bolt to the specified torque.
1«1 Torque N-m (lb-ft) 35 (26)
NOTE:
• Always use new gaskets.
• Be sure to put the hooked edge of the flexible
hose end into the anti-rotation cavity.
Rear Axle Brake Hose
1. Tighten the brake pipes to the specified torque.
1«1 Torque N-m (lb-ft) 16 (12)
2. Tighten the bolt to the specified torque.
1«1 Torque N·m (lb·in) 13 (113)

SA-8 HYDRAULIC BRAKES
BRAKE PIPE REPLACEMENT
Removal steps
1. Brake pipe
2. Plastic
clip
I nstallation
steps
To install, follow the removal steps in the reverse order.
Fig. 5A-3
1••1 REMOVAL
Preparation:
• Raise the vehicle and support it with suitable
safety stands.
• Remove wheel and tire assembly as necessary.
• Clean dirt, grease, and other foreign material
off the pipe fittings at both ends.
1. Brake pipe
2. Plastic clip
1••1 INSTALLATION
To install, follow the removal steps in the reverse
order, noting the
following points. After installing the
brake pipes,
bleed brakes as described in this section.
1. Tighten the brake pipes to the specified torque.
~~~ Master cylinder side 12 (104 lb·in) Torque
N·m(lb·ft) Others 16(12)

COMBINATION VALVE/P & B
(PROPORTIONING AND BYPASS) VALVE
The combination valve/P & B valve contains two
sections, each serving a different function.
The proportioning section
of the combination valve/
P & B valve proportions outlet pressure to the rear
brakes after a predetermined rear
input pressure has
been reached. This is done to prevent rear
wheel lock­
up on the vehicles with light rear wheel loads.
The valve has a By-pass feature which assures full
system pressure to the rear brakes in the event of a
front brake system malfunction, also full front pressure
is retained in the event
of rear brake malfunction.
HYDRAULIC BRAKES 5A 9
The combination valve has a pressure differential
warning switch which is designed to constantly
compare front and rear brake pressure
from the
master
cylinder and turn on the brake system warning
light on the instrument panel in the event of a front or
rear system malfunction. The valve and switch are so
designed that the switch
will latch in the "warning"
position once a malfunction has occurred. The only
way the light can be turned off is to repair the
malfunction and
apply a pedal force required to
develop line pressure. The combination valve/P & B
valve is not repairable and must be replaced as a
complete assembly.
P&B valve
(Antilock brake system model only)
Master cylinder (Primary)
Combination valve (Rear wheel antilock model only)
Pressure differential warning switch
Master
cylinder (Secondary)
..(> ..(> Master cylinder (Secondary) Master
cylinder
(Primary)
..(> ..(>
Front brake
Rear brake
Combination Valve
Electrical Circuit Test (RWAL
model
Fig. 5A-4
only)
1.
2.
3.
Disconnect the wmng connector at the
combination
valve (Fig. 5A-5).
• Connect a jumper wire from the harness to
ground.
Turn the ignition key to
"ON".
•
The warning light should come on.
• If the light will not come on, check the bulb. If
the bulb is good, refer to Chassis Electrical
(Sec.
8) for further diagnosis.
Turn the ignition off.
• Disconnect jumper wire and connect the
harness to the switch
terminal.
Combination Valve (RWAL model only)
Warning
Switch Test
1. Raise the vehicle.
• Support
with suitable safety stands.
2. Attach a hose to a rear brake bleeder screw.
• Immerse the opposite end of the hose into a
container
partially filled with clean brake fluid.
3.
4.
5.
6.
7.
¢ Front RH brake
Front LH brake
Rear brake
• Make sure the master cylinder reservoir is full.
Turn the ignition key to "ON".
• Open
the bleeder screw while a helper applies
moderate pressure to the brake pedal.
•
The warning light should come on.
• Close the bleeder screw before the helper
releases
the brake pedal.
Reapply the brake pedal with moderate to heavy
pressure.
• The light should go out.
Attach a hose
to a front brake bleeder screw.
• Immerse the opposite end of the hose into a
container
partially filled with clean brake fluid.
• Make sure the master cylinder reservoir is full.
Turn the ignition key to "ON".
• Open
the bleeder screw while a helper applies
moderate pressure to the brake pedal.
•
The warning light should come on.
• Close the bleeder screw before the helper
releases
the brake pedal.
Reapply
the brake pedal with moderate to heavy
pressure.
• The light should go out.

5A-1 0 HYDRAULIC BRAKES
8. Turn the ignition key off.
• If the warning light does not come on during
steps 3 and
6, but does light when a jumper is
connected to ground, the warning switch
portion
of the valve is faulty. Do not
disassemble any portion of the valve. It must
be replaced.
9. Remove the safety stands.
• Lower the vehicle.
• Check and fill the master cylinder to the proper
level.
VALVE REPLACEMENT
Removal steps 1. Hydraulic pipes
2. Warning switch
connector (Combination valve only)
3. Bolt
4. Combination valve/P&B valve
Installation
steps
To install, follow the removal steps in the reverse order.
Fig. 5A-5
1••1 REMOVAL
• The combination valve/P & 8 valve is not
repairable and must be replaced as a complete
assembly.
• Care must be taken to prevent brake fluid from
contacting any painted surface.
1. Hydraulic pipes
• Plug the pipes to prevent the loss of fluid or the
entrance
of dirt.
2. Warning switch connector (Combination valve
only)
3. Bolt
4. Combination valve/P & B valve
1••1 INSTALLATION
4.
3. Combination valve/P & B valve
Bolt
I~I_T_o_r_qu_e_N_·_m_(lb_·_in_) ___,_ ___ 1_3_(_1_13_) __ _
2. Warning switch connector (Combination valve
only)
1. Hydraulic pipes
~~~ Torque N·m (lb·ft) 16 (12)
After installing the brake pipes, bleed brakes as
described in this section.
•

INSPECTION OF BRAKE PAD LINING
(Fig. SA-6)
Inspect the brake linings any time the wheels are
removed (tire rotation, etc.). Check both ends
of the
outer pad by
looking at each end of the caliper. These
are the points at which the highest rate
of wear
normally occurs. At the same time, check the lining
thickness on the inner shoe to make sure that it was not
worn prematurely. Some inboard shoes and linings
have a thermal layer against the shoe, integrally
molded
with the lining. This extra layer should not be
confused with uneven inboard-outboard lining wear.
Look
down through the inspection hole in the top of the
caliper to view the inner shoe. Whenever the thickness
of any lining is worn to within 1 mm (0.039 in) of the
shoe,
all disc brake pad and lining assemblies should
be replaced at the same time.
The disc pads have a
wear indicator that makes a noise
when the pad wear to a degree where replacement is
required.
100
Limit 11.0 mm (0.039 in) I
Fig. 5A-6
INSPECTION OF BRAKE ROTORS
In manufacturing the brake rotor, tolerances of the
braking surfaces
for flatness, parallelism and lateral
runout are held very close. The maintenance of close
tolerance
on the shape of the braking surfaces is
necessary to prevent brake roughness.
In addition to these tolerances, the surface finish must
be held to a specified range. The control ofthe braking
surface finish is necessary to avoid
pulls and erratic
performance and to extend
lining life.
Light scoring of the rotor surfaces not exceeding
0.38mm (0.015 in) in depth, which may result from
normal use, is not detrimental to brake operation.
Thickness Variation Check (Fig. 5A-7)
1. Thickness variation can be checked by measuring
the thickness
of the rotor at four or more points
around the circumference
of the rotor. All
measurements must be made at 29 mm (1.14 in)
front/22 mm (0.87 in) rear from the edge of the
rotor.
HYDRAULIC BRAKES 5A-11
Fig. 5A-7
~~~ Front Disc Brake Rotor Thickness
Standard mm (in) 26.0 (1.024)
Limit mm(in) 24.6 (0.969)
~~~Rear Disc Brake Rotor Thickness
Standard mm (in) 18.0 (0.709)
Limit mm (in) 16.6 (0.654)
2. A rotor that varies by more than 0.010 mm
(0.0004 in) can cause pedal pulsation and/or front
end vibration during brake applications. A rotor
that does not meet these specifications should be
refinished
to specifications or replaced.
Lateral Runout Check (Fig. 5A-8)
1. Adjust the wheel bearing correctly.
• Refer to "Front Drive Axle" in Section 4C.
2. Install 2 wheel nuts to retain rotor.
3. Fasten a dial indicator to the suspension so that
the indicator stylus contacts the rotor about
29 mm (1.14 in)-front/22 mm (0.87 in)-rear from
the rotor edge.
4. Zero the dial indicator.
5. Move the rotor one complete revolution and
observe
total indicated runout.
Fig. 5A-8

SA-12 HYDRAULIC BRAKES
ltilU Maximum rotor runout mm (in) 0.13 (0.005)
• If
runout is greater than the limit, replace or
refinish the rotor.
Replacing Brake Rotors
When installing new brake rotors, do not refinish the
surfaces,
as these parts are at the correct level of
surface finish.
Refinishing Brake Rotors
Accurate control of the rotor tolerances is necessary
for proper performance of the 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. Do not use a
brake rotor
that will not meet the specifications, as
shown in the "Thickness variation check".
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.
Rear Drum (in Disc) Inside Diameter Check
Check the rear drum inside diameter by measuring at
more than
two portions as shown in Fig. 5A-9.
If the inside diameter is greater than the limit, replace
the rear rotor.
Fig. 5A-9
Rear Drum
Inside Diameter
ltil!.l Standard mm (in)
Limit
mm (in)
210.0 (8.27)
211.4 (8.32)
•

HYDRAULIC BRAKES SA-13
BRAKE PEDAL ASSEMBL V
CHECKING PEDAL HEIGHT (Fig. SA-1 0)
The push rod serves as the brake pedal stopper when
the pedal is fully released. Brake pedal height
adjustment
should be performed as follows:
I~FI Adjust brake pedal
1. Measure the brake pedal height after making sure
the pedal is
fully returned by the pedal return
spring. Pedal height
(L2) must be measured after starting
the engine and revving
it several times (Fig. 5A-
10).
1~1 Pedal Free Play (L 1) mm (in) 6-10 (0.23- 0.39)
Pedal Height (L2)
NOTE:
mm (in) 208-218
(8.19-8.58)
Pedal free play (L 1) must be measured after turning off
the engine and stepping on the brake pedal firmly five
times
or more.
2. If the measured value is not within the above
range, adjust the brake
pedal as follows:
a) Disconnect the stoplight switch connector.
b) Loosen the stoplight switch lock nut.
c) Rotate the stoplight switch so that it moves
away
from the brake pedal.
d) Loosen the lock nut on the push rod.
e) Adjust the brake pedal to the specified height
by rotating the push rod in the appropriate
direction.
f) Tighten the lock nut to the specified torque.
~~~ Torque N·m (lb·ft) 20 (15) --------~----~---
Fig. 5A-10
g) Adjust the stoplight switch to the specified
clearance (between switch housing and brake
pedal)
by rotating the switch housing (Fig. 5A-
11 ).
1@1 Clearance mm (in) I 0.5-1.0 (0.02-0.04)
NOTE:
While adjusting the stoplight switch, make sure that
the threaded part of the stoplight switch does not push
the brake
pedal.
h) Tighten the stoplight switch lock nut.
i) Connect the stoplight switch connector.
Fig.
5A-11
CHECKING PEDAL TRAVEL (Fig. SA-1 0)
1. Pedal height (L3) must be measured after starting
the engine and revving
it several times to apply
vacuum
to the vacuum booster fully.
NOTE:
Pedal height (L3) must be 55 mm (2.2 in) or more when
about 50 kg (11 0.25 I b) of stepping force is applied.
2. If the measured value is lower than the above
range, air existing in the hydraulic system is
suspected and perform bleeding procedure.

5A-14 HYDRAULIC BRAKES
BRAKE PEDAL REPLACEMENT
5
3
1
13
Removal steps MIT
1. Shift knob 6. Anti-theft controller 12. Pin, fulcrum
2. Front console assembly 7. Stoplight switch connector 13. Brake pedal
3. Lower cluster assembly
4.1nstrument panel
driver lower
cover
5. Driver knee bolster assembly
8. Return spring
9. Snap pin
10. Pin
11. Nut
Installation steps
To install, follow the removal steps
in the reverse order.
Fig. 5A-12
EJ REMOVAL
1. Shift knob
2. Front console assembly
3. Lower cluster assembly
4. Instrument panel driver lower cover
5. Driver knee bolster assembly
6. Anti-theft controller
7. Stoplight switch connector
8. Return spring
9. Snap pin
10. Pin
11.
Nut
12. Pin, fulcrum
13. Brake pedal
1•+1 INSTALLATION
13.
Brake pedal
12. Pin, fulcrum
§)• Apply grease to the entire circumference of the
fulcrum pin.
~~~ Torque N·m (lb·ft) ___ __._ ___ _ 33 (24)
11. Nut
~~~--T-o-rq_u_e __ N-.m--(-lb-.ft-)-.-----3-3-(-24_) ____ _
10. Pin
r:::;:] • Apply grease to the entire circumference of the
D push rod pin. ·
9. Snap pin
f;C1 • Adjust pedal free travel. Refer to "Brake Pedal
lED Adjustment" previously in this section.
8. Return spring
7. Stoplight switch connector
6. Anti-theft connector
5. Driver knee bolster assembly
4. Instrument panel driver lower cover
3. Lower cluster assembly
2. Front console assembly
1. Shift knob
•