1998 ISUZU TROOPER brake pads

5C – 6 POWER ASSISTED BRAKE SYSTEM
Condition Possible Cause Correction
Brake Drag1. Master cylinder pistons not returning 1. Adjust stop light switch and vacuum
correctly. booster operating rod. If necessary,
rebuild.
2. Restricted brake pipes or hoses. 2. Check for soft hoses or damaged pipes,
and replace with new hoses and new
double-walled steel brake piping.
3. Parking brake maladjusted. 3. Adjust.
4. Parking brake lining clearance 4. Adjust.
insufficient.
5. Brake pedal free play insufficient. 5. Adjust brake pedal height or power
cylinder operating rod.
6. Piston in master cylinder sticking. 6. Replace.
7. Piston in disc brake caliper sticking. 7. Replace piston seals.
8. Brake pads sticking in caliper. 8. Clean.
9. Return spring weakened. 9. Replace.
10. Parking brake binding. 10. Overhaul parking brakes and correct.
11. Front hub bearing preload incorrect. 11. Adjust or replace.
12. Parking brake shoes not returning. 12. Correct or replace brake back plate and
brake shoe as necessary.
13. Obstructions in hydraulic circuit. 13. Clean.
14. Rotor warped excessively. 14. Grind or replace.
15. Rear brake drum distorted. 15. Grind or replace.
16. Parking cable sticking. 16. Clean or replace.
Grabbing or1. Malfunctioning vacuum booster. 1. Check operation and correct as
Uneven necessary.
Braking Action 2. Binding brake pedal mechanism. 2. Check and lubricate, if necessary.
(All conditions3. Corroded caliper assembly. 3. Clean and lubricate.
listed under
“Pulls”)
Brake Noisy1. Brake pads worn. 1. Replace.
2. Brake pads hardened. 2. Replace.
3. Brake pads in poor contact with rotor. 3. Correct.
4. Brake disc(s) warped, worn or 4. Grind or replace.
damaged.
5. Disc brake anti-squeak shims fatigued. 5. Replace.
6. Front hub bearings loose or preload is 6. Adjust or replace.
incorrect.
7. Brake disc rusted. 7. Grind or replace.
Poor Brake1. Master cylinder faulty. 1. Correct or replace.
Action2. Vacuum booster faulty. 2. Correct or replace.
3. Level of brake fluid in reservoir too 3. Replenish and bleed.
low.
4. Air in hydraulic circuit. 4. Bleed.
5. Disc brake caliper faulty. 5. Clean or replace.
6. Water or oil on brake pads. 6. Clean or replace.
7. Brake pads in poor contact with rotor. 7. Correct.
8. Brake pads worn. 8. Replace.
9. Brake disc rusted. 9. Grind or replace.
10. Check valve in vacuum hose faulty. 10. Correct or replace.

5C – 14 POWER ASSISTED BRAKE SYSTEM
CHECKING BRAKE PEDAL TRAVEL
1. Pedal height (L3) must be measured after starting
the engine and removing it several times to apply
vacuum to the vacuum booster fully.
NOTE:
Pedal height (L3) must be 100 mm (3.9 in)/85 mm (3.5
in) (LHD/RHD) or more when about 50 kg (110.25 lb)
of stepping force is applied.
2. If the measured value is lower than the above
range, air existing in the hydrauic system is
suspected and perform bleeding procedure.
FRONT AND REAR DISC BRAKE PADS
INSPECTION
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.
The disc pads have a wear indicator that makes a
noise when the pad wears to where replacement is
required.
Minimum Limit mm (in)
1.0 (0.039)
SERVICING THE FRONT BRAKE ROTOR
In the manufacturing of the front 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.
t

5C – 24 POWER ASSISTED BRAKE SYSTEM
DISC BRAKES
The disc brake assembly consists of a caliper, piston, rotor, pad assembly and support bracket. The
caliper assembly has a single bore and is mounted to the support bracket with 2 mounting bolts. The
support bracket allows the caliper to move laterally against the rotor. The caliper is a one-piece casting
with the inboard side containing the piston bore. A square cut rubber seal is located in a groove in the
piston bore which provides the hydraulic seal between the piston and the cylinder wall.
NOTE:
1) Replace all components included in repair kits used to service this caliper.
2) Lubricate rubber parts with clean brake fluid to ease assembly.
3) If any hydraulic component is removed or disconnected, it may be necessary to bleed all or part of
the brake system.
4) Replace pads in axle sets only.
5) The torque values specified are for dry, unlubricated fasteners.
6) Perform service operation a clean bench free from all mineral oil materials.
OPERATION
Hydraulic pressure, created by applying the brake pedal, is converted by the caliper to a stopping force.
This force acts equally against the piston and the bottom of the caliper bore to move the piston outward
and to move (slide) the caliper inward resulting in a clamping action on the rotor. This clamping action
forces the linings against the rotor, creating friction to stop the vehicle.
Front disc brakes
Rear disc brakes

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.

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