tires ISUZU TROOPER 1998 Service Service Manual

5A±56
BRAKE CONTROL SYSTEM
Chart B-24 Sensor Signal Input Abnormality (DTC 65)
StepActionYe sNo
1Using TECH 2?Go to Step 2Go to Step 3
21. Connect TECH 2.
2. Select Snap shot manual trigger.
3. With wheel speed data displayed, run the vehicle when speed
has arrived at 30 km/h (18 mph).
4. Check speed data on each wheel (refer to the criterion given
below). *1
Is the abnormal sensor condition found?
Replace.
Go to Step 8
Go to Step 3
All the sensors
should follow the
following
flowchart (without
using TECH 2).
3Is there play in sensor/sensor ring?Repair.
Go to Step 8
Go to Step 4
4Is there powdered iron sticking to sensor/sensor ring?Repair.
Go to Step 8
Go to Step 5
5Is there a broken tooth or indentation in sensor ring?Replace sensor
ring.
Go to Step 8
Go to Step 6
6Is there play in wheel bearing?Adjust or repair.
Go to Step 8
Go to Step 7
7Is the check wiring between sensor and EHCU normal?
Replace EHCU.
Go to Step 8
Repair, and
perform system
self-check.
Go to Step 8
81. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat ªBasic
diagnostic flow
chart.º
Go to Step 8
Sensor Signal Abnormality Criteria using
TECH 2
1. While driving, the speed of one or two wheels 25% or
more higher than that of the other wheels.
2. The speed of one or two wheels is 10 km/h (6 mph) or
more higher than that of the other wheels.
3. During steady driving, wheel speed changes abruptly.
*1 The vehicle must run on a level paved road.
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop.
Turn the ignition switch to the ON position and drive the
vehicle at 12 km/h or higher to make sure that the warning
light goes out.
It is important to verify that the correct tires are installed
on vehicle.

POWER ASSISTED BRAKE SYSTEM 5C – 3
BRAKE SYSTEM DIAGNOSIS
ROAD TESTING THE BRAKES
Brake Test
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake
performance cannot be made if the roadway is wet,
greasy or covered with loose dirt so that all tires do
not grip the road equally. Testing will also be
adversely affected if the roadway is crowned so as to
throw the weight of the vehicle toward wheels on one
side or if the roadway is so rough that wheels tend to
bounce. Test the brakes at different vehicle speeds
with both light and heavy pedal pressure; however,
avoid locking the wheels and sliding the tires. Locked
wheels and sliding tires do not indicate brake
efficiency, since heavily braked but turning wheels
will stop the vehicle in less distance than locked
wheels. More tire-to-road friction is present with a
heavily braked turning tire then with a sliding tire.
The standard brake system is designed and balanced
to avoid locking the wheels except at very high
deceleration levels.
It is designed this way because the shortest stopping
distance and best control is achieved without brake
lock-up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake
Performance
1. Tires: Tires having unequal contact and grip on the
road will cause unequal braking. Tires must be
equally inflated, identical in size, and the tread
pattern of right and left tires must be
approximately equal.
2. Vehicle loading: A heavily loaded vehicle requires
more braking effort.
3. Wheel Alignment: Misalignment of the wheels,
particularly in regard to excessive camber and
caster, will cause the brakes to pull to one side.
BRAKE FLUID LEAKS
With engine running at idle and the transmission in
“Neutral”, depress the brake pedal and hold a
constant foot pressure on the pedal. If pedal gradually
falls away with the constant pressure, the hydraulic
system may be leaking.
Check the master cylinder fluid level. While a slight
drop in reservoir level will result from normal lining
wear, an abnormally low level in resevoir indicates a
leak in the system. The hydraulic system may be
leaking internally as well as externally. Refer to
“Master Cylinder Inspection”. Also, the system may
appear to pass this test but still have slight leakage. If
fluid level is normal, check the vacuum booster push

POWER ASSISTED BRAKE SYSTEM 5C – 5
TROUBLESHOOTING
Condition Possible Cause Correction
Brake Pull1. Tire inflation pressures unequal. 1. Adjust
2. Front wheel alignment incorrect. 2. Adjust
3. Unmatched tires on same axle. 3. Tire with approx. the same amount of
tread should be used on the same axle.
4. Restricted brake pipes or hoses. 4. Check for soft hoses and damaged
lines. Replace with new hoses and new
double-walled steel brake piping.
5. Water or oil on brake pads. 5. Clean or replace.
6. Brake pads hardened. 6. Replace.
7. Brake pads worn excessively. 7. Replace.
8. Brake rotor worn or scored. 8. Grind or replace.
9. Disc brake caliper malfunctioning. 9. Clean or replace.
10. Front hub bearing preload incorrect. 10. Adjust or replace.
11. Loose suspension parts. 11. Check all suspension mountings.
12. Loose calipers. 12. Check and tighten bolts to specifications.
Brake 1. Excessive lateral runout. 1. Check per instructions.
Roughness-orIf not within specifications, replace or
Chattermachine the rotor.
(Pulsates)2. Parallelism not within specifications. 2. Check per instructions.
If not within specifications, replace or
machine the rotor.
3. Wheel bearings not adjusted. 3. Adjust wheel bearings to correct
specifications.
4. Pad reversed (steel against iron). 4. Replace brake pad and machine rotor
to within specifications.
Excessive 1. Malfunctioning vacuum booster. 1. Check vacuum booster operation and
Pedal repair, if necessary.
Effort2. Partial system failure. 2. Check front and rear brake system for
failure and repair. Also, check brake
warning light. If a failed system is
found, the light should indicate a
failure.
3. Excessively worn pad. 3. Check and replace pads in sets.
4. Piston in caliper stuck or sluggish. 4. Remove caliper and rebuild.
5. Fading brakes due to incorrect pad. 5. Remove and replace with original
equipment pad or equivalent.
6. Vacuum leak to vacuum booster. 6. Check for ruptured or loose hose.
7. Check direction of check valve within 7. Correct vacuum hose direction.
vacuum hose.
8. Grease on the brake pads. 8. Replace or clean.
Excessive 1. Air in hydraulic circuit. 1. Bleed hydraulic circuit.
Brake Pedal 2. Level of brake fluid in resevoir too low. 2. Replenish brake fluid resevoir to
Travelspecified level and bleed hydraulic
circuit as necessary.
3. Master cylinder push rod clearance 3. Adjust.
excessive.
4. Leakage in hydraulic system. 4. Correct or replace defective parts.

POWER ASSISTED BRAKE SYSTEM 5C – 47
FRONT DISC BRAKE
BRAKE PADS REPLACEMENT
Outer side1
2
3
45
5
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.
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.
Preparation:
1) Draw out two-thirds of the brake fluid from the
reservoir.
2) Raise the vehicle and support it with suitable
safety stands.
1. Wheel and Tire Assembly
•Refer to Wheels and Tires in Suspension section.

POWER ASSISTED BRAKE SYSTEM 5C – 49
3. Caliper Assembly
1) Use adjustable pliers to bottom the piston into the
caliper bore. Be careful not to damage the piston
dust boot.
2) Do not damage the flexible hose by twisting or
pulling it.
2. Lock Bolt
Lock Bolt Torque N·m (kg·m / lb·ft)
74 (7.5 / 54)
1. Wheel and Tire Assembly
1) Refer to Wheels and Tires in Suspension section.
2) 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.

5C – 50 POWER ASSISTED BRAKE SYSTEM
REMOVAL
Raise the vehicle and support with suitable safety
stands
1. Wheel and Tire Assembly
•Refer to Wheels and Tires in Suspension section.
2. Brake Flexible Hose
1) Remove the bolt and gaskets, then disconnect the
flexible hose from the caliper.
2) After disconnecting the flexible hose, cap or tape
the openings to prevent entry of foreign material.
3) Since the brake fluid flows out from the
connecting coupler, place a drain pan under the
vehicle.
CALIPER REPLACEMENT
Outer side
4
3
2
758
8
6
1
Removal Steps
1. Wheel and tire assembly
2. Brake flexible hose
3. Guide bolt
4. Lock bolt
5. Caliper assembly
6. Support bracket with pad assembly
7. Pad assembly with shim
8. Clip
Installation Steps
To install, follow the removal steps in the
reverse order.

5C – 52 POWER ASSISTED BRAKE SYSTEM
5. Caliper Assembly
4, 3. Lock Bolt and Guide Bolt
Lock Bolt and Guide Bolt Torque N·m (kg·m / lb·ft)
74 (7.5 / 54)
2. Brake Flexible Hose
1) Always use new gaskets.
2) Be sure to put the hooked edge of the flexible
hose end into the anti-rotation cavity.
Brake Flexible Hose Torque N·m (kg·m / lb·ft)
35 (3.5 / 26)
1. Wheel and Tire Assembly
1) Refer to Wheels and Tires in Suspension section.
2) Bleed brakes. Refer to Bleeding Brake Hydraulic
System in this section.
Hooked edge
Gasket

5C – 56 POWER ASSISTED BRAKE SYSTEM
REAR DISC BRAKE
BRAKE PADS REPLACEMENT
1
5
5
3
2
4
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.
REMOVAL
NOTE:
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.
1) Draw out two-thirds of the brake fluid from the
reservoir.
2) Raise the vehicle and support it with suitable
safety stands.
1. Wheel and Tire Assembly
•Refer to Wheels and Tires in Suspension section.
2. Lock Bolt

5C – 58 POWER ASSISTED BRAKE SYSTEM
2. Lock Bolt
Lock Bolt Torque N·m (kg·m / lb·ft)
44 (4.5 / 32)
1. Wheel and Tire Assembly
1) Refer to Wheels and Tires in Suspension section.
2) 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.

POWER ASSISTED BRAKE SYSTEM 5C – 59
CALIPER REPLACEMENT
7
1
4
6
8
8
5
2
3
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.
REMOVAL
•Raise the vehicle and support with suitable safety
stands.
1. Wheel and Tire Assembly
•Refer to Wheels and Tires in Suspension section.
2. Brake Flexible Hose
1) Remove the bolt and gaskets, then disconnect the
flexible hose from the caliper.
2) After disconnecting the flexible hose, cap or tape
the openings to prevent entry of foreign material.
3) Since the brake fluid flows out from the
connecting coupler, place a drain pan under the
vehicle.