2002 ISUZU AXIOM tires

5C±44
POWER±ASSISTED BRAKE SYSTEM
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.

Draw out two±thirds of the brake fluid from the
reservoir.

Raise the vehicle and support it with suitable safety
stands.
1. Remove wheel and tire assembly, refer to
Wheels
and Tires System
in Section 3E.
2. Remove lock bolt (1)
306RW002
3. Rotate caliper assembly and support the caliper
assembly so that the brake hose is not stretched or
damaged.
4. Remove pad assembly with shim.
5. Remove clip.
Installation
1. Install clip (2).
306RW003
2. Apply special grease (approximately 0.2 g) to both
contacting surfaces of the inner shims. Wipe off
extruded grease after installing. Install pad assembly
with shim.
306RW004
Legend
(3) Inner Shim
(4) Wear Indicator

5C±45 POWER±ASSISTED BRAKE SYSTEM
306RW005
3. Carefyully use adjustable pliers to bottom the piston
into the caliper bore. Do not pull or twist the flex hose
or damage will occur.
302RS008
4. Install lock bolt (5) and tighten the bolt to the specified
torque.
Torque: 44 N´m (32 lb ft)
5. Install wheel and tire assembly, refer to
Wheels and
Tires System
in Section 3E.
6. 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.
306RW006

5C±48
POWER±ASSISTED BRAKE SYSTEM
Rear Disc Brake Caliper Assembly (4y4 Model)
Rear Disc Brake Caliper Assembly and Associated Parts
306RW007
Legend
(1) Brake Flexible Hose
(2) Clip
(3) Lock Bolt(4) Support Bracket
(5) Guide Bolt
(6) Pad Assembly with Shim
(7) Caliper Assembly
Removal
1. Raise the vehicle and support with suitable safety
stands.
2. Remove wheel and tire assembly, refer to
Wheels
and Tires System
in Section 3E.
3. Remove the bolt and gaskets, then disconnect the
flexible hose from the caliper and after disconnecting
the flexible hose (1), cap or tape the openings to
prevent entry of foreign material.
306RW008
4. Since the brake fluid flows out from the connecting
coupler, place a drain pan under the vehicle.5. Remove lock bolt (3).
6. Remove guide bolt (2).
306RW009
7. Remove caliper assembly.
8. Remove support bracket with pad assembly and take
care not to damage the flexible brake hose when
removing the support bracket.
9. Remove pad assembly with shim and mark the lining
locations if they are to be reinstalled.
10. Remove clip.

5C±50
POWER±ASSISTED BRAKE SYSTEM
302RW017
7. Install the wheel and tire assembly, refer to Wheels
and Tires System
in Section 3E.
8. Bleed brakes. Refer to
Hydraulic Brakes in this
section.
Rear Disc Brake Caliper (4y4 Model)
Rear Disc Brake Caliper Disassembled View
306RW014
Legend
(1) Guide Bolt
(2) Lock Bolt
(3) Bleeder with Cap
(4) Caliper Body(5) Piston Seal
(6) Piston
(7) Dust Boot: Piston
(8) Dust Boot Ring
(9) Dust Boot: Guide Bolt and Lock Bolt

5C±54
POWER±ASSISTED BRAKE SYSTEM
Brake Lining
Brake Lining and Associated Parts
305RW001
Legend
(1) Wheel and Tire Assembly
(2) Drum
(3) Hold-down Spring and Cup
(4) Hold-down Spring and Cups
(5) Lower Return Spring
(6) Upper (other) Return Spring
(7) Trailing Shoe Assembly with Parking Brake
Lever
(8) Leading Shoe Assembly with Upper (inner)
Return Spring(9) Upper (inner) Return Spring
(10) Auto Adjuster Lever
(11) Parking Brake Lever
(12) Adjuster Assembly
(13) Wave Washer
(14) Retainer
(15) Hold-down Pin
(16) Hold-down Pin
Removal
1. Raise the vehicle and support with suitable safety
stands.
2. Remove wheel and tire assembly (1).

Refer to
ªWheel and Tiresº in Wheel and Tire
System
section.
3. Remove Drum (2).

If difficulty is encountered in removing the drum:
± Mark the position of the drum to the axle.
± Make sure the parking brake is released.± Use a rubber mallet to tap gently on the outer rim of
the drum and/or around the inner drum. Be careful
to avoid damaging the drum.
4. Remove upper (other) return spring (6) and auto
adjuster lever.
5. Remove lower return spring (5).
6. Remove hold-down spring and cups (4) and
hold-down pin (15).
7. Remove adjuster assembly (12)
8. Remove leading shoe assembly (8) with upper (inner)
return spring (9).

5C±56
POWER±ASSISTED BRAKE SYSTEM
10. Install lower return spring (5).

Use brake spring tool.
11. Install auto adjuster lever (10).
12. Install upper (outer) return spring (6).

Use brake spring tool.
13. Install brake drum (2).

Adjust the brakes, refer to
Drum Brake Adjustment
in this section.
14. Install wheel and tire assembly (1).

Refer to
ªWheels and Tires º in wheel and Tire
System
section.
Drum Brake Adjustment (4y2 Model)
NOTE: All brakes are self-adjusting. Brakes are adjusted
by repeated stepping on the brake pedal. (After stepping
on the pedal and releasing it, the rear auto adjuster, in the
rear brake, produces a clicking sound.
The same operation should be repeated until the sound
disappears.)
Take the following steps after overhauling the rear brake
assembly.
1. Move the parking brake handle to its fully released
position.
2. Parking cable must be loosened sufficiently. (Loosen
the adjust nut and the lock nut.)
3. Repeat stepping on the brake pedal firmly, and
releasing it until the clicking sound can no longer be
heard.
If the difference between the brake drum inside
diameter and diameter of the brake shoes is adjusted
to be 0,5 mm, the number of times for depressing the
brake pedal can be reduced.
4. Remove the drum. Measure the brake drum inside
diameter and diameter of the brake shoes.
Shoe clearance: 0.25-0.4 mm (0.0098-0.0157 in)
If incorrect, check the brake auto-adjusting system.
5. Rotate the adjust nut until all slack disappears from
the cable. Set the adjust nut.
6. Applying about 30 kg (66 lb) of force, pull the parking
brake handle to its fully set position three or four
times.
7. If the parking brake is properly adjusted, the travel
between the fully disengaged position and the fully
engaged position will be between 9 and 11 notches.
If the traveling range is not within these limits, again
repeat steps 1 through 5.
After adjusting has been done, check to see if the rear
wheel rotates smoothly without drag when turned by
hand.
Servicing The Brake Drum
Whenever the brake drums are removed, they should be
thoroughly cleaned and inspected for cracks, scores,
deep grooves and out-of-round.
Cracked, Scored or Grooved Drum
A cracked drum is unsafe and must be replaced.
Do not attempt to weld a cracked drum.
Smooth any slight scores. Heavy or extensive scoring will
cause excessive brake lining wear, and it will probably be
necessary to machine the drum braking surface.
If the brake linings are slightly worn and the drum is
grooved, the drum should be polished with fine emery
cloth but should not be machined. At this stage,
eliminating all the grooves in the drum and smoothing the
ridges on the lining would require the removal of too much
metal and lining. If left alone, the grooves and ridges
match and satisfactory service can be obtained. If brake
linings are to be replaced, a grooved drum should be
machined. Using a grooved drum with new linings will
create inefficient braking performance and cause the
linings to wear quicker.
Out-Of-Round Drum
An out-of-round drum makes accurate brake shoe
adjustment impossible and is likely to cause excessive
wear to other parts of the brake mechanism due to its
eccentric action. An out-of-round drum can also cause
severe and irregular tire tread wear as well as a pulsing
brake pedal. When the braking surface of a brake drum
exceeds the specification limit of 0.15 mm (0.006 in) in
out-of-round, the drum should be machined to true up the
braking surface. Out-of-round can be accurately
measured with an inside micrometer fitted with proper
extension rods. When measuring a drum for out-of-round
and wear, take measurements at the open and closed
edges of machines surfaces and at right angles to each
other.
Maximum out-of-round: 0.15 mm (0.006 in)
420RS034

5C±66
POWER±ASSISTED 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 where 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. Braking without locking the tires will stop the
vehicle in less distance than braking to a skid (which has
no brake efficiency). More tire to road friction is present
while braking without locking the tires than braking to a
skid.
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 thread
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
ªNeutralº, 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
the reservoir level will result from normal lining wear, an
abnormally low level in reservoir 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 rod length. If an incorrect length
push rod is found, adjust or replace the push rod. Check
the brake pedal travel and the parking brake adjustment.
When checking the fluid level, the master cylinder fluid
level may be lower than the ªMAXº mark if the front and
rear linings are worn. This is normal.
Warning Light Operation
When the ignition switch is in the START position, the
ªBRAKEº warning light should turn on and go off when the
ignition switch returns to the ON position.
The following conditions will activate the ªBRAKEº light:
1. Parking brake applied. The light should be on
whenever the parking brake is applied and the ignition
switch is on.
2. Low fluid level. A low fluid level in the master cylinder
will turn the ªBRAKEº light on.
3. During engine cranking the ªBRAKEº light should
remain on. This notifies the driver that the warning
circuit is operating properly.

5C±67 POWER±ASSISTED BRAKE SYSTEM
General Diagnosis
ConditionPossible causeCorrection
Brake PullTire inflation pressure is unequal.Adjust
Front wheel alignment is incorrect.Adjust
Unmatched tires on same axle.Tires with approx. the same amount
of tread should be used on the same
axle.
Restricted brake pipes or hoses.Check for soft hoses and damaged
lines. Replace with new hoses and
new double walled steel brake
piping.
Water or oil on the brake pads.Clean or replace.
Brake pads hardened.Replace
Brake pads worn excessively.Replace
Brake rotor worn or scored.Grind or replace.
Disc brake caliper malfunctioning.Clean or replace.
Front hub bearing preload incorrect.Adjust or replace.
Loose suspension parts.Check all suspension mountings.
Loose calipers.Check and tighten the bolts to
specifications.
Brake Roughness or Chatter
(Pulsates)Excessive lateral runout.Check per instructions. If not within
specifications, replace or machine
the rotor.
Parallelism not within specifications.Check per instructions. If not within
specifications, replace or machine
the rotor.
Pad reversed (steel against iron).Replace the brake pad and machine
rotor to within specifications.
Excessive Pedal EffortMalfunctioning vacuum booster.Check the vacuum booster operation
and repair, if necessary.
Partial system failure.Check the front and rear brake
system for failure and repair. Also,
check the brake warning light. If a
failed system is found, the light
should indicate failure.
Excessively worn pad.Check and replace pads in sets.
Piston in caliper stuck or sluggish.Remove caliper and rebuild.
Fading brakes due to incorrect pad.Remove and replace with original
equipment pad or equivalent.
Vacuum leak to vacuum booster.Check for ruptured or loose hose.
Check the direction of check valve
within vacuum hose.Correct vacuum hose direction.
Grease on the brake pads.Replace or clean.
Excessive Brake Pedal TravelAir in hydraulic circuit.Bleed the hydraulic circuit.
Level of brake fluid in the reservoir
too low.Replenish brake fluid reservoir to
specified level and bleed hydraulic
circuit as necessary.
Master cylinder push rod clearance
excessive.Adjust
Leakage in hydraulic system.Correct or replace defective parts.